PLCs - Programmable Logic Controllers

A PLC (programmable logic controller) is an industrial digital computer designed for the control of manufacturing processes or robotic devices where reliability control, simple programming and fault diagnosis is necessary. They were originally built to replace electromechanical relay systems in industrial automation.

A CPU (central processing unit) forms part of the PLC system. PLC CPUs are microprocessor-based and act as the electronic circuitry within an industrial computer. They carry out instructions from the computer program, performing basic mathematical, logical, control, input and output operations. You can find out more in our complete PLCs guide.

What are PLCs used for?

PLC controllers are important for the correct functioning of machinery in manufacturing and industry. They are used in the automation of electromechanical processes, including control of machinery on assembly lines, amusement rides, or lighting fixtures. PLCs are ideal for applications that require constant monitoring of input devices whilst allowing decisions to be made via a custom program. This ultimately enables it to control an output.

Types of PLCs

Programmable logic controllers are divided into small, medium and large modular categories. Small control systems are robust, compact and mountable on top of or beside the equipment to be controlled. Medium controllers mainly use rack mounting or backplane systems, allowing for simple upgrading via additional function cards. Large systems are necessary for applications where complex control functions are executed, usually in large plants, in machinery requiring constant monitoring, or control of other PLC hardware.

What setups are suitable for programmable logic controllers?

PLCs feature a modular design, making them suitable for use in a wide range of applications. Due to the modular aspect, PLCs can be plugged into numerous setups making them highly versatile.


...
Read more Read less

Filters

Viewing 1 - 20 of 628 products
Results per page
Description Price For Use With Manufacturer Series Number of Inputs Number of Digital Inputs Output Type Input Type Number of Analogue Inputs Voltage Category Number of Digital Outputs Number of Analogue Outputs Interface Kit Included Number of Outputs Network Type
RS Stock No. 917-6370
BrandRS PRO
£81.85
Each
Units
- - 8 - Digital, Relay Analogue, Digital - - - - - - 4 ModBus
RS Stock No. 917-6361
BrandRS PRO
£81.30
Each
Units
- - 8 - Digital, Relay Digital - - - - - - 4 ModBus
RS Stock No. 917-6377
BrandRS PRO
£69.46
Each
Units
- - 8 - Digital, Relay Analogue, Digital - - - - - - 4 ModBus
RS Stock No. 917-6373
BrandRS PRO
£70.62
Each
Units
- - 8 - Digital, Relay Digital - - - - - - 4 ModBus
RS Stock No. 917-6389
BrandRS PRO
£42.69
Each
Units
RS PRO Logic Modules - 8 - Digital, Relay Digital - - - - - - 4 ModBus
RS Stock No. 917-6399
BrandRS PRO
£11.87
Each
Units
RS PRO Logic Modules - - - - - - - - - - - - -
RS Stock No. 917-6386
BrandRS PRO
£40.75
Each
Units
RS PRO Logic Modules - 8 - Digital, Relay Digital - - - - - - 4 ModBus
RS Stock No. 917-6392
BrandRS PRO
£33.59
Each
Units
RS PRO Logic Modules - 1 - RS485 Protocol (D-), RS485 Protocol (D+), RS485 Protocol (Two Wires) TTL Level - - - - - - 1 ModBus
RS Stock No. 917-6383
BrandRS PRO
£31.14
Each
Units
RS PRO Logic Modules - 1 - RS485 Protocol (D-), RS485 Protocol (D+), RS485 Protocol (Two Wires) TTL Level - - - - - - 1 ModBus
RS Stock No. 864-4538
Mfr. Part No.0850-0600
BrandBARTH
£104.86
Each
Units
STG-600 lococube mini-PLC 10 - PWM, Solid State Analogue, Digital - - - - - - 9 -
RS Stock No. 806-6837
Mfr. Part No.TM221CE16R
£202.00
Each
Units
- Modicon M221 9 - Digital Discrete - - - - - Yes 7 -
RS Stock No. 468-4242
Mfr. Part No.SR3B261BD
£207.10
Each
Units
- Zelio Logic 16 - Relay Analogue, Discrete - - - - - - 10 -
RS Stock No. 862-4471
Mfr. Part No.6ES7214-1AG40-0XB0
BrandSiemens
£369.00
Each
Units
SIMATIC S7-1200 Series S7-1200 14 (Digital Input, 2 switch as Analogue Input) - Digital, Transistor Analogue, Digital - 24 V dc - - - - 10 (Digital Output, Transistor Output) Ethernet
RS Stock No. 864-4541
Mfr. Part No.0660-0600
BrandBARTH
£117.70
Each
Units
STG-600 lococube mini-PLC 10 - Mosfet, Solid State Analogue, Digital - - - - - - 8 -
RS Stock No. 885-0926
Mfr. Part No.IS.MD21.base
£205.78
Each
Units
- M-Duino 13 - Analogue, Digital Analogue, Digital - 12 → 24 V dc - - - - 8 Ethernet, ModBus
RS Stock No. 539-0689
Mfr. Part No.FX3U-32MR/ES
BrandMitsubishi
£691.00
Each
Units
- FX3U 16 - Relay Sink, Source - - - - - - 16 -
RS Stock No. 442-0802
Mfr. Part No.AL2-24MR-D
BrandMitsubishi
£188.00
Each
Units
- Alpha 2 15 - Relay Digital - - - - - - 9 -
RS Stock No. 468-4258
Mfr. Part No.SR3B261FU
£209.00
Each
Units
- Zelio Logic 16 - Relay Discrete - - - - - - 10 -
RS Stock No. 468-4494
Mfr. Part No.SR2B201FU
£177.65
Each
Units
- Zelio Logic 12 - Relay Discrete - - - - - - 8 -
RS Stock No. 875-5672
Mfr. Part No.FX5U-32MR-ES
BrandMitsubishi
£656.50
Each
Units
MELSEC IQ-F Series IQ Platform-Compatible PLC FX5U 16 - Relay, Transistor Sink, Source - 100 → 240 V ac - - - - 16 Inverter Communication, MELSEC Communication protocol (3C/4C Frames), MELSOFT Connection, Modbus RTUI, N:N Network, Predefined Protocol Support, SLMP (3E Frame), Socket Communication