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Omron CS1W-CT021 — PLCs (Programmable Logic Controllers)

Omron CS1W-CT021 Counter Module, 4 Dig / 4 Solid State

MPNCS1W-CT021
End of Life

Omron CS1W series CS1W-CT021 counter module, 4 digital inputs and 4 solid-state outputs, backplane-mounted D-Sub termination, CS Series compatibility.

$405.77Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

CS1W-CT021 — Identification
ParameterValue
SeriesCS1W
CS1W-CT021 — I/O
ParameterValue
Inputs (count and type)4 - Digital
Outputs (count and type)4 - Solid State
CS1W-CT021 — Environmental
ParameterValue
Operating temperature range0°C~55°C
CS1W-CT021 — Mechanical
ParameterValue
Mounting typeBackplane
Weight0.54 lb (244.94 g)
Termination styleD-Sub
CS1W-CT021 — Approvals
ParameterValue
Approvals / certificationsCE, cULus, Lloyd, NK
CS1W-CT021 — Other specifications
ParameterValue
TypeCounter Module

Product details

What it does on the rack

The Omron CS1W-CT021 is a Counter Module in the CS1W series, sitting on the CS Series backplane and presenting four digital inputs against four solid-state outputs to the CPU scan. Field wiring lands on a D-Sub connector at the module face, so the pulse sources — encoders, proximity counters, flow-meter pulses — terminate to a single multi-pin plug rather than screw terminals. It runs across a 0°C~55°C ambient window and carries CE, cULus, Lloyd, and NK approvals, which covers the usual UL-panel and marine-class builds without a separate submittal package.

Closest functional sibling

The other CS1W siblings on file (CS1W-SCU31-V1, CS1W-ETN01) are Communications Modules and are not cross-shop candidates for a counter slot.

Panel-side fit

D-Sub termination keeps the wiring job on a single plug, which is the right choice when the four input sources are encoder or pulse lines and you want one crimp-and-go harness rather than four discrete terminal landings.

Frequently asked questions

When sourcing CS1W-CT021, what is the closest functional second-source — CS1W-CTS21?

CS1W-CTS21 matches on I/O count, backplane mounting, D-Sub termination and operating envelope, but it is listed as an Interface Module rather than a Counter Module — same slot, different functional class, so verify the counter-mode behavior in the application before treating it as a swap.

What is CS1W-CT021's listed type on this component line?

Counter Module, in the CS1W series.

Will CS1W-CT021 drop into a panel that was specified around CS1W-CTS21 without rewiring?

Mechanically yes — same CS1W backplane, same D-Sub field connector, same 0°C~55°C range — but functionally the CTS21 is an Interface Module, not a Counter Module, so the ladder logic and pulse-handling behavior need to be re-validated rather than assumed.

MPN
CS1W-CT021