MELSEC-Q is Mitsubishi Electric's modular PLC series: a CPU and power supply sit on a base unit, with I/O, analog, positioning and network modules in the slots. In September 2026 Mitsubishi Electric announced the discontinuation of almost the whole series (technical bulletin FA-A-0495-A), so this page is a guide for plants that still run MELSEC-Q systems: key dates, what the series offers and the migration options Mitsubishi points to (MELSEC iQ-R and MELSEC MX Controller).

MELSEC-Q Series lifecycle: key dates

• Most models (FA-A-0495-A, September 2026): make-to-order from 1 December 2028, last order acceptance on 30 September 2029 and production ends on 31 December 2029. Mitsubishi Electric notes that production may end earlier, depending on parts availability.
• Repair support: until 31 December 2036 (FA-A-0495-A), and repair may not be possible if parts run out. The AnyWireASLINK master QJ51AW12AL and the AnyWire DB A20 master QJ51AW12D2 are supported until 31 December 2030.
• C Controller modules (FA-A-0446-A): last order acceptance on 28 February 2030 and production ends on 29 March 2030.
• Motion CPUs and QD77MS simple motion modules (notice No.26-22E): production ends on 31 December 2029. QD77GF4, QD77GF8 and QD77GF16 (notice No.26-08E): production ends on 31 March 2029.
• Reason given by Mitsubishi Electric: the production of parts used has been discontinued one after another.
• Some individual models, for example the large-type I/O modules (FA-A-0483-A), have had certification marks removed. Please check Mitsubishi Electric's notices and your export and import requirements for your project.

These are Mitsubishi Electric's global dates and can change. Availability, order deadlines and lead times in Thailand are not yet confirmed. Mitsubishi Electric advises buying spares before the order deadline, so contact TKK for current stock, spare parts and migration advice.

Key features of the MELSEC-Q modular PLC

• Modular structure: the CPU and a power supply module sit on a main base unit, I/O and intelligent function modules go in the slots, and extension base units connect through extension cables.
• High-speed Universal model CPUs (Q03UDVCPU, Q04UDVCPU, Q06UDVCPU, Q13UDVCPU and Q26UDVCPU): 30K to 260K steps, LD instruction time of 1.9 ns and up to 4096 I/O points.
• Built-in Ethernet (100BASE-TX/10BASE-T) and USB on the High-speed Universal CPUs, with no RS-232 port. These CPUs also work as a CC-Link IE Field Network Basic master without a network module and support predefined protocols such as MODBUS/TCP and BACnet client.
• SD/SDHC card slot on the High-speed Universal CPUs for CSV data logging (with FTP transfer of the log files), boot operation and backup and restore, plus a port for an extended SRAM cassette. A password of up to 32 characters and blocking of unauthorized devices help protect the program.
• Programming with Mitsubishi Electric's GX Works2 engineering software in ladder, list, SFC, function block and structured text. The High-speed Universal CPUs are supported by GX Works2 only, not by GX Developer.

Expansion modules and networks

• Base units and power supplies: main base units Q33B, Q35B, Q38B and Q312B (3, 5, 8 and 12 slots), slim base units Q32SB, Q33SB and Q35SB, extension base units Q63B, Q65B, Q68B and Q612B, and power supply modules Q61P, Q62P, Q64PN (AC input) and Q63P (24 V DC input).
• Digital I/O modules: AC and DC input, relay, triac and transistor (sink or source) output, and combined input/output modules such as QX40, QX80, QY10, QY40P, QY80 and QH42P.
• Analog and temperature modules: analog input (Q64AD, Q68ADV, Q68ADI), analog output (Q62DAN, Q64DAN), thermocouple input Q64TD, RTD input Q64RD, temperature control (Q64TCTTN, Q64TCRTN), loop control Q62HLC, load cell input Q61LD and CT input Q68CT.
• Positioning and counting: QD75P1N, QD75P2N and QD75P4N (open collector output), QD75D1N, QD75D2N and QD75D4N (differential output) and high-speed counter modules such as QD63P6 and QD64D2.
• Network modules: Ethernet (QJ71E71-100), CC-Link IE Controller (QJ71GP21-SX), CC-Link IE Field (QJ71GF11-T2), CC-Link (QJ61BT11N), AnyWireASLINK (QJ51AW12AL) and serial communication (QJ71C24N).
• Open fieldbus modules: MODBUS (QJ71MB91 and QJ71MT91), PROFIBUS-DP (QJ71PB92V), EtherNet/IP (QJ71EIP71), FL-net (QJ71FL71-T-F01) and AS-i (QJ71AS92).
• These modules are covered by Mitsubishi Electric's discontinuation notices, so confirm availability with TKK before planning an expansion.

Choosing a CPU: Q03UDV to Q26UDV

TKK lists the five High-speed Universal model CPUs below. All five have a 1.9 ns LD instruction time, 4096 I/O points, built-in Ethernet and USB, an SD/SDHC card slot and no RS-232 port. Mitsubishi Electric lists them in FA-A-0495-A with last order acceptance on 30 September 2029.

• Q03UDVCPU: 30K steps and 120 KB program memory.
• Q04UDVCPU: 40K steps and 160 KB program memory.
• Q06UDVCPU: 60K steps and 240 KB program memory.
• Q13UDVCPU: 130K steps and 520 KB program memory.
• Q26UDVCPU: 260K steps and 1040 KB program memory.

The same notice also covers the Q00UJ, Q00U, Q01U and Q02U CPUs, the Q50UDEH and Q100UDEH CPUs and the Universal model process CPUs Q04UDPV, Q06UDPV, Q13UDPV and Q26UDPV. The specifications differ by variant (for example, Ethernet, RS-232 and SD card slot are not the same on every CPU), so check the exact model before ordering a spare.

Models in the series

Main MELSEC-Q models, with their status from Mitsubishi Electric notices. Contact TKK to check supply and replacements before you order.

• High-speed Universal CPUs: Q03UDVCPU, Q04UDVCPU, Q06UDVCPU, Q13UDVCPU and Q26UDVCPU. Last order 30 Sep 2029.
• Universal CPUs: Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q50UDEHCPU and Q100UDEHCPU. Last order 30 Sep 2029.
• Universal Process CPUs: Q04UDPVCPU, Q06UDPVCPU, Q13UDPVCPU and Q26UDPVCPU. Last order 30 Sep 2029.
• C Controller: Q12DCCPU-V, Q24DHCCPU-V, Q24DHCCPU-LS and Q26DHCCPU-LS. Last order 28 Feb 2030.
• Motion CPUs: Q172DSCPU, Q173DSCPU and Q170MSCPU. Production ends 31 Dec 2029.
• Power supplies: Q61P, Q62P, Q63P, Q64PN, Q61SP, Q61P-D, Q63RP and Q64RPN.
• Base units: Q33B, Q35B, Q38B, Q312B, Q35DB, Q38DB, Q312DB, Q32SB, Q33SB, Q35SB and Q38RB main bases; Q63B, Q65B, Q68B, Q612B, Q52B and Q55B extension bases.
• Digital I/O: QX10, QX28, QX40, QX41, QX42, QX80, QX81, QX82, QY10, QY18A, QY22, QY40P, QY41P, QY42P, QY80, QY81P, QH42P, QX48Y57, QX41Y41P and QI60.
• Analog: Q64AD, Q64ADH, Q68ADV, Q68ADI, Q62AD-DGH, Q66AD-DG, Q68AD-G, Q62DAN, Q64DAN, Q64DAH, Q68DAVN, Q68DAIN, Q62DA-FG, Q66DA-G and Q64AD2DA.
• Temperature and loop control: Q64TD, Q64TDV-GH, Q68TD-G-H01, Q68TD-G-H02, Q64RD, Q64RD-G, Q68RD3-G, Q64TCTTN, Q64TCRTN, Q64TCTTBWN, Q64TCRTBWN, Q62HLC, Q61LD and Q68CT.
• Positioning and counting: QD75P1N, QD75P2N, QD75P4N, QD75D1N, QD75D2N, QD75D4N, QD70P4, QD70P8, QD70D8, QD73A1, QD62, QD62D, QD62E, QD63P6, QD64D2, QD65PD2 and QD60P8-G.
• Simple Motion: QD77MS2, QD77MS4 and QD77MS16 (production ends 31 Dec 2029); QD77GF4, QD77GF8 and QD77GF16 (production ends 31 Mar 2029).
• Networks: QJ71E71-100, QJ71GP21-SX, QJ71GP21S-SX, QJ71GF11-T2, QJ61BT11N, QJ51AW12AL, QJ71C24N, QJ71C24N-R2, QJ71C24N-R4, QJ71MB91, QJ71MT91, QJ71PB92V, QJ71PB93D, QJ71EIP71, QJ71FL71-T-F01 and QJ71AS92.
• Information modules: QJ71MES96N, QD81DL96 and QJ71DC96.
• Memory and options: Q4MCA-1MBS to Q4MCA-8MBS SRAM cassettes, Q2MEM and Q3MEM memory cards and Q8BAT-SET. The Q6BAT, Q7BATN and Q8BAT batteries and A6CON connectors stay in production.

Migration options for MELSEC-Q systems

Mitsubishi Electric names the MELSEC iQ-R series and the MELSEC MX Controller as the replacement for MELSEC-Q, and publishes a MELSEC-Q to iQ-R migration guide (L(NA)08510ENG). The CPU examples below come from Mitsubishi Electric's tables. Compare the specifications of each model before you choose.

• High-speed Universal CPUs: Q03UDVCPU and Q04UDVCPU to R04CPU, Q06UDVCPU to R08CPU, Q13UDVCPU to R16CPU and Q26UDVCPU to R32CPU.
• Other Universal CPUs: Q00UJ and Q00U to R00CPU, Q01U to R01CPU, Q02U to R02CPU, and Q50UDEH and Q100UDEH to R120CPU. Process CPUs: Q04UDPV and Q06UDPV to R08PCPU, Q13UDPV to R16PCPU and Q26UDPV to R32PCPU.
• Base units: Q33B to R33B, Q35B to R35B, Q38B to R38B and Q312B to R312B.
• Positioning and simple motion: Mitsubishi Electric names the iQ-R RD75P2, RD75P4, RD75D2 and RD75D4 modules for the QD75 series, and the RD77MS modules for QD77MS. Wiring, specifications and buffer memory addresses differ by model, so check the MELSEC-Q to iQ-R migration guide (L(NA)08510ENG) before migrating.
• Analog modules: iQ-R analog modules have a Q compatible mode for some models. Check the migration guide for the buffer memory differences.
• Keeping existing Q modules: they can be used with an iQ-R CPU only through the RQ extension base units (RQ65B, RQ68B and RQ612B), and only the modules on Mitsubishi Electric's list.
• Programming: Q systems use GX Works2 and iQ-R systems use GX Works3, so projects must be converted.
• MELSECNET/H modules follow their own, earlier schedule (FA-A-0380-B). Mitsubishi Electric names iQ-R and CC-Link IE options depending on the model.
• C Controller and Motion CPUs: Mitsubishi Electric names R12CCPU-V, RD55UP06-V and RD55UP12-V for the C Controller (FA-A-0446-A) and R16MTCPU, R32MTCPU and R64MTCPU for the Motion CPUs (No.26-22E).
• MELSEC MX Controller: the bulletin names it as an option but gives no model-by-model list for MELSEC-Q, so ask TKK for advice.

iQ-R is not a drop-in replacement for MELSEC-Q. Program capacity, memory, speed and ports differ (for example, iQ-R CPUs have no RS-232 port, which some Q CPUs have), modules must be checked one by one and programs must be converted. TKK can help you compare your current MELSEC-Q configuration with the options and plan the move.

Contact TKK for spare parts, repair information and migration advice for your MELSEC-Q system.