CC-Link IE TSN Implementation: Migration Decisions, RFP and FAT/SAT for Thai Factories

When a Japanese-affiliated factory in Thailand considers CC-Link IE TSN implementation, the real decision is not whether to switch to a faster network. It is a planning question: before the MELSEC-Q maintenance deadlines arrive, which lines move to TSN, in what order, how far, and which parts stay on CC-Link IE Field. On top of that, the very advantage of carrying control traffic and IT traffic on the same cable also becomes an attack surface. That is why the implementation plan needs to include the network boundary and acceptance tests for diagnostics and maintenance from the very beginning.

This article is written so that production engineering and maintenance managers can assemble the material they need for internal decisions. It walks through how the technology works, how it differs from older networks, migration patterns, network design, security, how to think about cost, RFP items, what to check at FAT/SAT, and issues specific to Thailand. Note that all factory conditions, costs, downtime figures and reduction rates in this article are provisional numbers set up for this article only. They are not industry averages, survey results or manufacturer prices. When you evaluate your own case, replace them with your own downtime records and quotations.

Why CC-Link IE TSN Implementation Is on the Table for Thai Factories Now

In the second half of 2026, three developments have converged for production engineering departments at Japanese-affiliated factories in Thailand, making it hard to keep postponing a decision.

The first is the end of production of MELSEC-Q. In a technical bulletin issued in September 2026 (FA-A-0495-A), Mitsubishi Electric announced the end of production of many MELSEC-Q models, including general-purpose QCPUs, base units, I/O and network modules. The list also includes the CC-Link IE Field master/local module QJ71GF11-T2 and the CC-Link master/local module QJ61BT11N. For factories whose existing lines run on a combination of Q and IE Field, this means the network modules, not only the CPUs, are subject to replacement.

The second is a vulnerability advisory. On July 30, 2026, Mitsubishi Electric disclosed information tampering and denial-of-service (DoS) vulnerabilities in the CC-Link IE TSN communication protocol, and updated the advisory on September 17, 2026. If you newly adopt CC-Link IE TSN, the boundary design has to take this into account.

The third is plans for new lines and major modifications. As more incoming equipment arrives with control panels and servos that support CC-Link IE TSN, you have to decide how to connect it to existing IE Field lines, or whether to run the two separately.

These three look like separate topics, but in practice they come together in a single plan. If the timing of the Q replacement, the network method and the security boundary are not decided together, the result tends to be modifications done twice, or design gaps discovered after acceptance. The overall approach to PLC upgrades is also covered in “PLC Replacement and Retrofit: Zero-Surprise Migration for Thai Factories in 2026“.

What Is CC-Link IE TSN: Architecture, Classes and Certification

How the specification came about

On November 21, 2018, the CC-Link Partner Association (CLPA) announced the completion of the CC-Link IE TSN specification as the next-generation network of CC-Link IE. According to CLPA, CC-Link IE TSN is built on TSN technology at Layer 2 of the OSI reference model, while Layers 3 to 7 consist of CC-Link IE TSN’s own protocols plus standard Ethernet protocols. IEEE 802.1AS is used for time synchronization, and IEEE 802.1Qbv is used for sharing a single line by dividing it in time.

CLPA explains that this architecture makes it possible to perform control communication with real-time performance while handling traffic from other open networks and information exchange with IT systems on the same network. It has the advantage of reducing wiring, but as discussed in a later section, it makes boundary design indispensable.

In addition to 1 Gbps, the communication speed can also be 100 Mbps. CLPA explains that, besides implementation with dedicated ASICs or FPGAs, the protocol can also be implemented as a software protocol stack on general-purpose Ethernet chips, for both master stations and device stations.

Specification values and product limits are not the same thing

In CLPA’s network specification table, the number of connectable nodes per network is given as 64,770 (master and device stations combined). However, this is a value in the specification. According to Mitsubishi Electric’s published figures, the actual product limits are a maximum of 121 stations per network (including the master station) for the iQ-R master/local modules RJ71GN11-T2 and RJ71GN11-EIP, and a maximum of 61 stations for the iQ-F FX5-CCLGN-MS when used as a master station. What matters in design is the product limit, so the RFP and design documents should always list the model numbers to be used alongside the limit for each model.

CLPA states a maximum distance between nodes of 100 m with twisted-pair cable and 550 m with multimode optical fiber, and line, star, mixed line/star and ring topologies. Here too, the supported range differs by product. According to Mitsubishi Electric’s published specifications, the RJ71GN11-T2 supports line, star and ring, whereas the RJ71GN11-EIP supports line and star only, and the FX5-CCLGN-MS also supports line and star only.

Certification classes A and B

According to CLPA’s developer pages, CC-Link IE TSN has certification classes A and B depending on the functions and performance of devices and Ethernet switches, with class B being the higher class. For class B devices, compliance with IEEE 802.1AS and IEEE 802.1Qbv, synchronization accuracy of 1 μs or better, and the time-division method are mandatory. Class A is to be developed only when modifying the software of existing non-TSN products, and CLPA recommends developing class B.

For users, the important point is the following note. According to CLPA, guaranteeing 1 μs time-synchronization accuracy requires that the system be built only from class B certified products and that no class A product (including Ethernet switches) be placed between class B products. In addition, the master station must be able to communicate with both class A and class B device stations. In other words, connecting class A devices is possible in itself, but depending on where they are placed, the premise of synchronization accuracy can break down.

Switches also have certification classes. According to CLPA, both class A and class B require compliance with 1000BASE-T or 100BASE-TX, Auto MDI/MDI-X and auto-negotiation, and class B additionally requires IEEE 802.1AS compliance, synchronization accuracy of 1 μs or better, and IEEE 802.1Qbv compliance.

What the conformance test means

According to CLPA, all certified CC-Link family products sold by partner companies have passed the conformance test. The test consists of hardware tests, software tests, verification of the device profile (CSP+) and aging tests. However, CLPA clearly states that the test confirms conformance to the communication specification, does not cover device-specific functions, and passing it does not guarantee the performance or quality of the product itself. It is not a reason to skip acceptance testing.

For reference, CLPA reports that as of the end of March 2026 it had more than 4,538 corporate members and a cumulative total of more than 3,543 CC-Link family compatible products. These are figures for the entire family, not for CC-Link IE TSN alone.

Regarding international standardization, CLPA states that CC-Link IE TSN was published in IEC 61158 in March 2023, CC-Link IE Controller/Field/TSN in IEC 61784-2-8 in March 2023, and CC-Link IE TSN in SEMI E54.23 in May 2020 (all dates are first-edition publication dates).

Figure 1: Example CC-Link IE TSN configuration separated from the office LAN by a firewall. An iQ-R master, a class B managed switch, servos, remote I/O and an HMI sit on the TSN side, and the existing CC-Link IE Field segment is kept beyond the NZ2GN-GFB bridge.

CC-Link IE TSN vs CC-Link IE Field, CC-Link and Field Basic

The table below compares CC-Link IE TSN with the networks still found on existing lines, based on CLPA’s specification tables and explanations.

The device counts in the table are specification values. The actual limit is determined by the products you use (see the previous section).

The biggest difference is how communication is controlled. According to CLPA, the conventional CC-Link IE uses token passing, in which the node holding the token (the right to transmit) sends its data and then passes the token to the next station. CC-Link IE TSN uses synchronized time and sends output and input frames in both directions simultaneously at scheduled times, which shortens the update time of cyclic data. It also allows multiple communication cycles to be used on the same network.

Be careful about conditions when you put performance figures in internal documents. According to Mitsubishi Electric Thailand’s published figures, the minimum communication cycle of 31.25 µs is the value when the motion module RD78GH is used in high-speed operation mode. “16 times faster” is a comparison with CC-Link IE Field Network Motion, and “twice the link points” is a comparison with CC-Link IE Field. If you drop these conditions and write “switching to TSN makes it 16 times faster”, expectations will diverge at acceptance.

CC-Link (an RS485 bus) supports up to 64 devices, and at 10 Mbps the maximum total cable length is 100 m. Where it remains on older equipment, it will often be better to prioritize securing spare parts and sorting out the replacement timing before moving to TSN.

Choosing a CC-Link IE TSN Migration Pattern

There are three broad ways to migrate. Which one is right depends on the remaining life of each line and its renewal plan.

Pattern K: Keep as is and secure spare parts

Secure spare Q CPUs, IE Field modules and remote stations, and keep running as is for the time being. The cost looks small, but it only postpones the cost of migration. According to Mitsubishi Electric, repair support for MELSEC-Q continues until December 31, 2036 (with two AnyWire-related models as exceptions), but spare parts must be secured by September 30, 2029, the end of order acceptance. This pattern suits equipment with a short remaining life, or lines scheduled to be replaced entirely within a few years.

Pattern B: Staged migration (iQ-R master and bridge)

Replace the line master with iQ-R and the RJ71GN11-T2, and keep the existing IE Field stations via a bridge. According to Mitsubishi Electric Thailand, the bridge module NZ2GN-GFB can be used as a remote station on CC-Link IE TSN and as a master station or local station on CC-Link IE Field. However, the NZ2GN-GFB does not function as a CC-Link IE TSN master station, so a separate master station is required on the TSN side.

The advantage of this approach is that you do not have to rewire remote I/O and servos that are still usable all at once. On the other hand, the stations on the IE Field side keep running with token passing, so the benefits of TSN time synchronization are limited to the TSN segment. How faults on the IE Field side appear on the TSN-side diagnostics screen also needs to be checked in acceptance testing.

Pattern T: Full TSN conversion

In addition to the master, replace the servos with CC-Link IE TSN compatible models and install class B managed switches in the star-topology sections. Compatible models listed in Mitsubishi Electric Thailand’s published information include the servo amplifiers MR-J5-G, MR-J5W-G, MR-J5-G-RJ, MR-J5D-G4 and MR-JET-G; the inverters FR-A800-GN and FR-E800-E/SCE (1 Gbps support for the FR-E800-E/SCE is planned via a future option); the CR800-R for MELFA FR robots; and the GT25-J71GN13-T2 communication unit for GOT2000 (used as a local station; some models such as the GT2505 are not supported).

Because full TSN conversion involves rewiring and replacing servos, it makes the most sense when done together with a major modification of the equipment or a new installation.

Existing simple motion modules also have deadlines. According to Mitsubishi Electric, for the CC-Link IE Field compatible simple motion modules QD77GF4/8/16 and RD77GF4/8/16/32, the shift to build-to-order production is March 31, 2027, order acceptance runs until March 31, 2028, end of production is March 31, 2029, and repair acceptance runs until March 31, 2036. The iQ-R motion modules RD78G4/RD78G8/RD78G16 are indicated as replacements for the QD77GF4/8/16, and for the RD77GF series customers are advised to consult a sales office. In addition, the QD77GF and RD77GF are not planned to comply with the EU Cyber Resilience Act (CRA), and units ordered from April 2027 onward are stated to be supplied without CE marking. For motion equipment upgrades, see also “Equipment Control Retrofit: MELSEC-Q Motion Migration in Thailand“.

MELSEC-Q End of Production Schedule and Migration Planning

Mitsubishi Electric’s published schedule is as follows.

As replacement models, Mitsubishi Electric indicates MELSEC iQ-R or MELSEC MX controllers. Under “future initiatives”, the bulletin lists, as planned for October 2026, the addition of a support function for editing projects carried over from GX Works2 in GX Works3, and, as planned for April 2027, the extension of that support function to intelligent modules and network modules. Both are plans, so please confirm whether they are actually usable once they become available.

The point to watch is the practical deadline, counted back from the end of order acceptance. Whether you buy spare parts or design a migration, once you account for quotations, internal approval, ordering and lead times, acting just before September 30, 2029 may be too late. The end-of-production date may also be brought forward depending on parts availability.

In Thailand, Mitsubishi Electric Factory Automation (Thailand) is also running a “Product Migration Campaign” until March 31, 2027 (or while stocks last). According to the company’s announcement, it covers iQ-F/iQ-R PLCs, MELSERVO J5, FR-800 inverters and GOT3000, and the benefits are free software (subject to conditions), free product training, and one additional year on top of the standard warranty. This is a sales-side announcement, and it explicitly states that the conditions may be changed or discontinued without notice. Please confirm the applicable conditions with your sales representative or an authorized distributor.

Figure 2: MELSEC-Q end-of-production timeline. It shows the September 2026 announcement, the March 31, 2027 deadline of the Thai migration campaign (a vendor sales measure), the shift to build-to-order production on December 1, 2028, the end of order acceptance on September 30, 2029, the end of production on December 31, 2029, and the end of repair and security support on December 31, 2036.

When upgrading from a Q CPU to iQ-R, program handover and recovery testing also need to be built into the plan. Reading “Mitsubishi PLC Program Handover: Recovery Testing for Thai Factories” alongside this article will help reduce gaps in the work.

Network Design in Practice for CC-Link IE TSN Implementation

Base the station count on the product limit

As noted earlier, design to the limit of the products you use, not to the specification value of 64,770. That is a maximum of 121 stations (including the master station) for the RJ71GN11-T2, and a maximum of 61 stations as a master station for the FX5-CCLGN-MS. Prepare a station list that includes future expansion, and record in the design documents how much margin you have against the limit.

Rules for mixing classes A and B

As CLPA explains, 1 μs synchronization accuracy is guaranteed only when the system is built solely from class B products and no class A product (including switches) is inserted between class B products. When equipment is procured through different machine builders, a class A device or switch can slip in somewhere. The reliable approach is to have the builders submit a list of model numbers and certification classes for all stations and check the connection order on the configuration drawing.

Choosing switches

Mitsubishi Electric Thailand’s specification page specifies that, where switches are used, managed Ethernet switches compatible with CC-Link IE TSN (class B) recommended by CLPA should be used. The company’s own products include the managed switches NZ2MHG-TSNT4 (4 ports) and NZ2MHG-TSNT8F2 (8 ports) for star configurations, and TCP/IP devices can be connected to their free ports. However, Mitsubishi Electric notes that these two models were developed and manufactured by Moxa, and that their specifications and warranty conditions differ from those of the MELSEC series. The service window for spare parts and repairs may not be the same as for the PLC, so check this before procurement. Selection of general-purpose industrial switches is covered in detail in “Selecting an Industrial Ethernet Switch for a Thai Factory: RFP to SAT“.

Mixing 100 Mbps devices

According to Mitsubishi Electric Thailand, when 100 Mbps devices and 1 Gbps devices are mixed on the same network, the 100 Mbps devices are connected after the 1 Gbps compatible (class B) devices. If there are devices connected at 100 Mbps, such as inverters, state the connection order clearly on the drawings.

Communication cycles and robots

Being able to use multiple communication cycles on the same network is a feature of CC-Link IE TSN, but some devices have restrictions. According to Mitsubishi Electric’s technical news (February 2026), the network base card 2F-DQ535-TSN for the D type of the CR800/CR860 robot controllers can be connected as a remote station and does not support “Mixed Cycle Time”. When connecting a robot fitted with this card, the communication cycle interval setting for all coexisting devices must be 1000 µs or more. In addition, the HMS Anybus CompactCom M40 must be provided by the customer. On lines that include robots, decide the communication cycle design at an early stage.

Ring and redundancy

According to Mitsubishi Electric, the RJ71GN11-T2 supports ring topology, and in a ring configuration data communication with healthy stations continues even if a cable breaks or a device station fails. The RJ71GN11-EIP does not support ring and is stated to be connectable only at the end of the network. If you adopt a ring, first check whether the master you use supports it. Redundancy methods in general are compared in “Industrial Network Redundancy Design: MRP, RSTP, PRP and HSR“.

Safety communication

According to CLPA, the CC-Link IE safety communication function meets the requirements necessary for IEC 61508 SIL3 compliance and follows the basic concept of functional safety communication in IEC 61784-3. Safety stations and standard stations can also be mixed on the same network. According to Mitsubishi Electric, the RJ71GN11-T2 can be used as a safety master/local station in combination with an iQ-R safety CPU (up to 120 connections per station). If safety functions are to be carried over the network, decide the division of responsibility for safety circuit design and verification at the RFP stage.

CC-Link IE TSN Security: The Advisory, Mitigations and Boundary Design

What the advisory says

In advisory 2026-005, Mitsubishi Electric disclosed information tampering and DoS vulnerabilities (CVE-2026-13584) in the CC-Link IE TSN communication protocol. The CVSS v4 base score is 7.1, the initial release was July 30, 2026, and the last update was September 17, 2026. According to Mitsubishi Electric, an attacker with access to a CC-Link IE TSN network could potentially tamper with control input/output values by sending crafted packets under specific timing conditions. The vulnerability was reported by Nozomi Networks.

The affected products listed include the master/local modules RJ71GN11-T2/SX/EIP, FX5-CCLGN-MS, MR-J5-G series servos, FR-A8NCG/FR-A800-GN/FR-E800-E/SCE, some GOT3000 models, GT25-J71GN13-T2, the NZ2GN-GFB bridge, the 2F-DQ535-TSN for robots and MELSEC MX controllers, all listed as “All versions”. In other words, many of the main products named in this article as migration targets are affected. Always check the Mitsubishi Electric PSIRT page for the latest information, including the availability of fixed versions.

Mitigations recommended by Mitsubishi Electric

The mitigations Mitsubishi Electric recommends in the advisory are as follows.

• Restrict physical access to the affected products and the CC-Link IE TSN network they are connected to (access control at the installation site)
• Lock the control panels that house the affected products and network equipment
• Block Ethernet ports, for example with port locks
• Use the products within a trusted network in which communication with untrusted networks and hosts is blocked by a firewall or similar
• Configure credentials and access rights on boundary devices appropriately

None of these is a special technique, but whether they are actually observed on the shop floor is another matter. Habits such as plugging a maintenance laptop into a free port, unlocked panels, and equipment vendors’ remote maintenance lines are commonly seen in factories in Thailand as well.

CLPA guidelines

CLPA has announced that Mitsubishi Electric (a CLPA board member company) issued the advisory based on advice from Nozomi Networks, and asks users to also refer to the CC-Link IE TSN Security Guidelines published by CLPA (overview and detailed editions) when building and operating systems. On its security page, CLPA gives examples of threats and countermeasures: IDS/IPS functions against ransomware infection via external devices, bandwidth limiting and network filtering (setting permitted source IP addresses in the engineering tool) against DoS attacks, and authentication functions (remote password) against tampering by impersonation. Downloading the detailed edition is limited to CLPA members.

Where to draw the boundary

CLPA explains that control communication and IT communication can be integrated on the same network. CLPA also explains that with SLMP, a PC on the office LAN can access CC-Link IE and CC-Link devices across networks to set parameters and collect maintenance information. This is convenient, but the flip side is that it creates a path from the office side to the control side.

In practice, always place a firewall between the TSN side and the office LAN, and list and approve the traffic that is allowed through (a rule table). If you place a monitoring PC or an SNMP collection server on the TSN side, manage that PC itself as a control-side device. For equipment vendors’ remote maintenance, the basic approach is to define the connection times and paths and not to keep the connection permanently open. OT/IT segmentation design is covered in “Industrial Network Construction 2026: OT/IT Segmentation Design for Factories“, and procurement and acceptance of security measures in “Implementing OT Security in Thailand: RFP and FAT/SAT Acceptance“.

How to Think About the Cost and Payback of CC-Link IE TSN Implementation

What follows is a model calculation. To repeat, all figures below are provisional numbers set independently for this article. They are not industry averages, survey results or manufacturer prices. Please read them as an example of the way of thinking.

Assumptions for Model Factory M

• A Japanese-affiliated electrical components factory in eastern Thailand (Chonburi Province), not an automotive parts plant, with six assembly and inspection lines
• Each line consists of a MELSEC-Q CPU, a CC-Link IE Field master (QJ71GF11-T2), remote I/O, and servos driven via simple motion modules
• Network-related stoppages (cable breaks, connectors, station faults, configuration errors) total 18 per year across all six lines. Each takes an average of 2.5 hours from identifying the cause to recovery, for a total of 45 hours per year
• If the loss from a line stoppage is provisionally set at THB 30,000 per hour, the annual loss is THB 1,350,000

Comparing the three patterns

The downtime reduction assumes that, of the 45 hours per year, B cuts 13.5 hours (30%) and T cuts 22.5 hours (50%).

Figure 3: Simple payback periods in the model calculation. B (staged migration) is approx. 8.9 years and T (full TSN conversion) is approx. 19.6 years, while K (keep as is) involves spare-part costs only with no payback (all calculated from this article’s provisional values).

What the calculation tells us

What this calculation shows is that if you count only the reduction in downtime as the benefit, both B and T take a long time to pay back. Even if diagnostic functions and automatic parameter distribution speed up recovery, it would be difficult to justify the investment on that basis alone.

The decision criteria lie elsewhere. One is which lines to replace, and when, before the MELSEC-Q deadlines for order acceptance (September 30, 2029) and repair (December 31, 2036). The other is to make new or heavily modified lines TSN from the start. B is a means of bringing forward and spreading the deadline response across fiscal years, while T makes sense when done together with equipment renewal.

Cautions to avoid double counting

• K, B and T are mutually exclusive options. Do not add their benefits or costs together
• The downtime reduction rates for B and T (30% and 50%) are assumptions, not values guaranteed by the manufacturer
• K’s spare-part cost of THB 900,000 merely postpones the migration cost that will eventually be needed, and does not replace it
• Quality, safety and security benefits are not included in the monetary figures. Including them would require separate evidence for each (defect records, accident risk assessments and so on). Adding unsupported benefits tends to result in counting the same downtime twice

12 Items to Include in an RFP for CC-Link IE TSN Implementation

When requesting quotations from machine builders or system integrators, including the following 12 items in the RFP makes it easier to compare proposals and carry out acceptance.

1. List of model numbers and stations: Model numbers and quantities of existing and new CPUs, network modules, remote stations, servos, inverters and HMIs. Also have the bidder attach the results of cross-checking against the MELSEC-Q end-of-production list
2. Migration pattern: Which of K, B or T is assumed. For B, which stations remain on the IE Field side
3. Certification classes and switches: Certification class of every station, switch model numbers and certification classes, and a configuration drawing with no class A device between class B devices
4. Verification method for communication cycle and station count: How the designed communication cycle and station count will be verified, test duration and pass/fail criteria
5. Handling of the bridge: When using the NZ2GN-GFB, the model of the TSN-side master, allocation of IE Field-side stations, and how they appear in diagnostics
6. Compatible drive and HMI models: Compatible model numbers and communication speeds for servos, inverters, robots and GOTs. Connection order of 100 Mbps devices
7. Diagnostic and maintenance functions: Scope of diagnostics in GX Works3, error history, automatic parameter distribution and SNMP collection
8. Security boundary and mitigations: Firewall location and rule table, port blocking, panel locking, and how the advisory’s mitigations will be implemented
9. Conditions for IT traffic coexistence: Traffic volume of monitoring PCs and data collection carried on the same network, and how the impact on control communication will be verified
10. Shutdown plan and changeover procedure: Downtime on the changeover day, rollback procedure, storage of old modules
11. FAT/SAT criteria: Test items and pass/fail criteria based on the items in the next section
12. Documentation, training and spare parts: Procedures in Thai and English, configuration drawings, parameter backups, training for maintenance staff, number of spares

For estimating data collection traffic, see “PLC Data Collection 2026: Tag Count and Polling Interval Decide It, Not the Protocol“, and for control panel specifications, “Control Panel Design for Thailand: Circuit, Thermal and FAT“.

What to Check at CC-Link IE TSN FAT/SAT

The following are example acceptance test items. Figures for time and counts are provisional target examples for this article, not values from any standard.

FAT (before shipment from the builder’s factory)

• Configuration check: Have the builder submit, before FAT, a list of model numbers, firmware versions and certification classes for all stations, and confirm on the drawings that there is no class A device between class B devices. According to Mitsubishi Electric, firmware of CC-Link IE TSN compatible devices can be updated (contact the sales office for the update tool and files), so recording version numbers is essential
• Station count and cycle: Run continuously with the designed station count and communication cycle (for example, 8 hours) with no communication errors recorded
• Cable break and disconnection tests: Unplug cables at the end of the line, in the middle and downstream of a switch, and check whether GX Works3 diagnostics can pinpoint the location and whether communication recovers automatically after reconnection. For ring configurations, also check whether communication continues with a break on one side
• Device replacement test: Replace a remote station with a spare and confirm that it recovers through automatic parameter distribution without individual configuration
• Mixing 100 Mbps devices: If they are mixed, check connection order and operation
• IT traffic coexistence: With a monitoring PC and SNMP collection on the same network, confirm there is no impact on control communication
• Bridge configuration: Confirm that IE Field-side stations can be read from the TSN-side master, and how faults on the IE Field side appear in TSN-side diagnostics

According to Mitsubishi Electric, GX Works3 can display the CC-Link IE TSN system configuration in connection order and pinpoint cable breaks and fault locations. Each station is stated to share time-stamp information in 1 ms increments, allowing error history to be displayed in chronological order. By importing device profiles (CSP+), products including those from partners can be managed centrally. According to CLPA, SNMP is also supported, so information including switches and routers can be collected with general-purpose monitoring tools. These functions are not useful merely because they exist, so at FAT actually break a cable, check the screens, and confirm that maintenance staff can read those screens.

SAT (after on-site installation)

• Security: Blocking of free ports, panel locking, the boundary between the TSN side and the office LAN (firewall rule table), and records of implementing the mitigations described in the advisory
• Documentation: Maintenance procedures in Thai and English (for cable breaks and replacements), network configuration drawings, parameter backups
• Post-start-up records: Record the number of communication errors and stoppages for 30 days after start-up and compare them with the current baseline (for Model Factory M, the breakdown of the 45 hours per year)

Although the standard is different, the approach to acceptance of diagnostics has much in common with “PROFINET Network Diagnostics: RFP and FAT/SAT Guide“.

Issues Specific to Thailand and ASEAN

1. Existing plants mix Q, IE Field and CC-Link

In Thai factories it is normal to have equipment installed at different times side by side: Q with IE Field, even older CC-Link lines, and different HMIs for each machine. Start by taking an inventory of model numbers and listing the maintenance deadline for each model. For how to build the asset register, see “OT Asset Management Implementation: Inventory, RFP and 90-Day Acceptance for Thai Factories“.

2. Spare parts and repair service windows

CLPA has announced that it opened an office in Thailand in April 2016, and in 2025 it exhibited at Modern Manufacturing Forum 2025, held in Rayong (May 8), Chonburi (July 24), Korat (August 21), Songkhla (September 25) and Chiang Mai (November 6). It is one of the local channels for gathering information on the standard.

The Mitsubishi Electric Factory Automation (Thailand) migration campaign mentioned above is a sales measure running until March 31, 2027. The conditions for the benefits need to be confirmed with a distributor. Also, because some products, such as the Moxa-made managed switches, have warranty conditions that differ from the PLC, decide the repair service window and where spares are kept for each product.

3. Networks differ from one machine builder to another

When you buy equipment from Japanese, Chinese and local Thai machine builders, the network method, switches and device choices differ from builder to builder. It is effective to specify the CC-Link IE TSN certification class, the station count limit, switch conditions and diagnostic requirements at the equipment specification stage. Writing the conditions in at the time of ordering reduces rework compared with aligning things afterwards.

4. BOI efficiency improvement measure

Thailand Board of Investment (BOI) Announcement No. 15/2565 (effective January 3, 2023) includes a measure for improving efficiency through machinery upgrades and automation. According to the BOI’s unofficial English translation, existing projects, both BOI-promoted and non-BOI, are eligible, and for BOI-promoted projects the condition is that the corporate income tax exemption period has expired or was never granted. The minimum investment is THB 1 million, excluding land cost and working capital. The incentives are exemption of import duty on machinery and a 3-year corporate income tax exemption on income from the existing business (capped at 50% of the investment), with the cap rising to 100% if linkage with the domestic automation industry accounts for 30% or more of the total automation system value. The project must be completed within 3 years from the date the certificate is issued. The BOI guide states that investment in software that is integrated with machinery and controls, supervises or supports the manufacturing process can also be counted.

However, this article could not confirm whether the measure is still accepting applications as of 2026. In addition, the BOI guide states that activities such as general automobile manufacturing (3.6) and PHEV/HEV manufacturing (3.8) are not eligible under this measure. For the automotive sector there is a separate special measure for automation and robotics under Announcement No. 4/2569, and according to a law firm’s summary, applications are accepted until the end of 2027. In either case, if you are considering using these measures, please check individually with the BOI or a professional advisor.

5. Remote maintenance and equipment vendor connections

In Thailand, Japanese and Chinese machine builders often perform maintenance remotely. Make clear on the drawings where such connections enter the TSN side, and include them in the firewall rule table. Also set operational rules for bringing in maintenance PCs and for direct connections to free ports.

6. Rolling out to sites in Vietnam

The model number list and acceptance test items created in Thailand can be used as they are at other sites, such as in Vietnam. Using the same list and the same tests also makes it easier to compare sites. However, laws, subsidies and incentive schemes differ by country, so please check them individually in each country.

Latest Developments and Adjacent Standards

TSN over 5G verification

On February 24, 2026, SoftBank, Murata Manufacturing and CLPA announced the results of operating CC-Link IE TSN devices in a laboratory private 5G environment. According to the announcement, the average time-synchronization error over 5G was 122 ns, and CC-Link IE TSN compatible remote I/O and a PLC connected over 5G maintained synchronization accuracy within 1 µs during more than 6 hours of continuous communication, meeting class B requirements. This was a laboratory demonstration, at a stage before commercialization.

Switch IC and wireless LAN certification

On December 17, 2025, CLPA announced that Analog Devices’ TSN switch ICs ADIN6310 (6 ports) and ADIN3310 (3 ports) passed switch certification class B and class A in the recommended wiring component tests. They are reported to have obtained certification at both 100 Mbps and 1 Gbps. In addition, according to press coverage (MONOist), Contec announced on April 17, 2025 that its FLEXLAN FX5000 and FX3000 series business wireless LAN products obtained wireless certification class A, category CTRL, in the CC-Link IE TSN recommended wireless device test, and the company states that this is the first class A certification for a wireless device.

Adjacent standards

According to the IEEE 802.1 page, IEC/IEEE 60802, the TSN profile for industrial automation, was published as a standard on June 29, 2026. In April 2022, CLPA joined TIACC, which develops a common conformance test plan for the 60802 profile. For PROFINET, according to PI, specification V2.4 integrates TSN as an additional Layer 2 technology. For OPC UA FX, we have been able to confirm that the OPC Foundation released the first four parts (controller-to-controller communication) in 2022, but please check the latest information on subsequent extensions. The approach to OPC UA FX implementation is covered in “OPC UA FX Implementation: RFP and FAT/SAT for Thai Factories“, and time synchronization, the foundation of TSN, in “Factory Time Synchronization: PTP vs NTP and Acceptance Tests in Thailand“.

Whichever method you choose, what matters in Thai factories is the support structure of the PLC manufacturer you use and whether there are people locally who can fix things. For choosing a PLC manufacturer, see also “PLC Selection 2026: How Many More Years Can You Repair the Panel?“.

A 90-Day Plan for CC-Link IE TSN Migration

Days 0 to 30: Inventory and understanding the current state

• List the model numbers and quantities of CPUs, network modules, remote stations, servos and inverters on all lines
• Cross-check against the end-of-production lists for MELSEC-Q and simple motion modules, and add columns for the order acceptance deadline and repair deadline
• Compile the past year of network-related stoppage records and produce the number of incidents, hours and breakdown of causes

Days 31 to 60: Direction and draft design

• Compare the K/B/T migration patterns for each line and arrange them by cost and deadline
• Prepare a draft network design (station count, classes, switches, 100 Mbps devices, ring)
• Prepare a draft security boundary (firewall location, draft rule table, remote maintenance paths)
• Issue the RFP

Days 61 to 90: Acceptance criteria and pilot

• Finalize FAT/SAT items and pass/fail criteria
• Select the pilot line to migrate first
• Compare quotations and make the ordering decision. If you are considering using BOI incentives, check with the BOI by this stage

Frequently Asked Questions

What is the difference between CC-Link IE TSN and CC-Link IE Field?

The biggest difference is how communication is controlled. According to CLPA, IE Field uses token passing, in which the token is handed on in turn, while CC-Link IE TSN uses time synchronization to send in both directions simultaneously at scheduled times. CLPA explains that CC-Link IE TSN also supports 100 Mbps, allows multiple communication cycles on the same network, and can be integrated with IT communication.

With MELSEC-Q reaching end of production, what do we need to decide, and by when?

According to Mitsubishi Electric, the shift to build-to-order production is December 1, 2028, order acceptance runs until September 30, 2029, end of production is December 31, 2029 (it may be brought forward), and repair runs until December 31, 2036. Whether to buy spares or migrate needs to be decided well before the order acceptance deadline, taking quotations, internal approval and lead times into account. Start with an inventory of model numbers.

Can existing CC-Link IE Field devices be used together with CC-Link IE TSN?

With Mitsubishi Electric’s NZ2GN-GFB bridge, you can keep existing stations, with the bridge acting as a remote station from the TSN side and as a master or local station on the IE Field side. However, the NZ2GN-GFB does not become a TSN master, so a separate master station is required on the TSN side. Please check in acceptance testing how faults on the IE Field side appear in TSN-side diagnostics.

How should we deal with the CC-Link IE TSN vulnerability (CVE-2026-13584)?

Mitsubishi Electric’s advisory (last updated September 17, 2026) lists as mitigations: access control at the installation site, locking control panels, blocking Ethernet ports with port locks, use within a trusted network protected by a firewall or similar, and configuring credentials and access rights on boundary devices. Please also refer to CLPA’s security guidelines. Check Mitsubishi Electric PSIRT for the latest information, including the availability of fixed versions.

Which switches should we choose for CC-Link IE TSN?

Mitsubishi Electric Thailand’s specification page specifies the use of class B compatible managed switches recommended by CLPA. According to CLPA, guaranteeing 1 μs synchronization accuracy requires building the system only from class B products and not inserting class A devices (including switches) between class B devices. Note that Mitsubishi Electric’s NZ2MHG-TSNT4/TSNT8F2 are made by Moxa and their warranty conditions differ from those of MELSEC products.

What should we check in the RFP and acceptance tests (FAT/SAT) for CC-Link IE TSN?

In the RFP, specify items such as the list of model numbers and stations, certification classes and switches, the verification method for communication cycles, handling of the bridge, the security boundary, and FAT/SAT criteria. At FAT, actually perform cable break tests, device replacement tests and operation with IT traffic mixed in; at SAT, check the records of mitigation implementation and post-start-up stoppage records. For matters involving incentives such as the BOI’s or legal requirements, please check individually with the relevant authorities or professional advisors.

Summary

CC-Link IE TSN implementation is not about making the network faster. It is about planning which lines to migrate, and how, before the MELSEC-Q deadlines. Design to the product limit rather than the specification value of 64,770, build configurations with no class A device between class B devices, and choose class B compatible switches recommended by CLPA. Because the ability to carry IT traffic on the same cable is also an attack surface, include the mitigations shown in the 2026 advisory and the boundary with the office LAN in the plan from the start. As the model calculation showed, reducing downtime alone leads to long payback periods. Combining a staged migration that spreads out the response to the deadlines with full TSN conversion timed to new installations and major modifications, and verifying each design assumption one by one through the RFP and FAT/SAT, may look like a detour but is the reliable way forward.

TOMAS TECH can help even from the early stages, such as taking an inventory of model numbers, comparing migration patterns, or preparing the RFP and acceptance criteria. We will work with you to sort out where to start, in line with the realities of your factory in Thailand. Please get in touch through our contact form.

References

• CLPA: Press release on completion of the CC-Link IE TSN specification (November 21, 2018)
• CLPA: Features of CC-Link IE TSN
• CLPA: Network specifications
• CLPA: CC-Link IE TSN development flow (certification classes)
• CLPA: Conformance test
• CLPA: Global activities (members and compatible products)
• CLPA: International standardization
• CLPA: SLMP
• CLPA: Safety communication
• CLPA: Security notice
• CLPA: CC-Link IE TSN security
• CLPA: News (Thailand office opening, joining TIACC)
• CLPA: Events
• CLPA: Announcement of TSN over 5G verification (February 24, 2026)
• CLPA: ADI switch ICs pass certification (December 17, 2025)
• Mitsubishi Electric Factory Automation (Thailand): Hub and bridge products
• Mitsubishi Electric Factory Automation (Thailand): CC-Link IE TSN specifications
• Mitsubishi Electric Factory Automation (Thailand): Master station products
• Mitsubishi Electric Factory Automation (Thailand): Drives and HMI
• Mitsubishi Electric Factory Automation (Thailand): Performance and diagnostics
• Mitsubishi Electric Factory Automation (Thailand): Time stamps and mixed devices
• Mitsubishi Electric Factory Automation (Thailand): Automatic parameter distribution and ring
• Mitsubishi Electric Factory Automation (Thailand): Product Migration Campaign
• Mitsubishi Electric: Technical news on the network base card for robots (February 2026)
• Mitsubishi Electric: Technical bulletin FA-A-0495-A on MELSEC-Q end of production
• Mitsubishi Electric: Notice of end of production for QD77GF/RD77GF No.26-08E
• Mitsubishi Electric PSIRT: Advisory 2026-005 (CVE-2026-13584)
• BOI: Announcement No. 15/2565 (unofficial English translation)
• BOI: Smart and Sustainable Industry (investment promotion guide 2023)
• Tilleke & Gibbins (republished on Mondaq): Overview of new incentives for the automotive sector
• MONOist: Article on Contec wireless LAN obtaining wireless certification class A
• IEEE 802.1: IEC/IEEE 60802
• PI: PROFINET over TSN
• OPC Foundation: Release of the first OPC UA FX specifications (December 2022)