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Serial Remote I/O Modules for RS-232, RS-422, and RS-485 Networks

Serial Remote I/O modules provide reliable signal acquisition and control via RS-232, RS-422, or RS-485 interfaces. These modules offer dependable connectivity for legacy and modern industrial systems alike, especially useful if you're handling sensor inputs, relay outputs, voltage readings or TTL signals.

Contact our team for advice on selecting the right Serial I/O module for your specific application.

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Showing 60 of 73 Serial Remote I/O Modules items

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2 options available

Moxa ioLogik R1241 Series

RS-485 to 4 Analog Output Module – Modbus RTU

From £336.50 (exc. VAT)

2 options available

Moxa ioLogik R1240 Series

RS-485 to 8 Analog Input Module – Modbus RTU

From £272.00 (exc. VAT)

2 options available

Moxa ioLogik R1210 Series

RS-485 to 16 Digital Input Module – Modbus RTU

From £166.50 (exc. VAT)

2 options available

Moxa ioLogik R1212 Series

RS-485 to 8 Digital Input / 8 Digital I/O Module – Modbus RTU

From £191.00 (exc. VAT)

2 options available

Moxa ioLogik R1214 Series

RS-485 to 6 Digital Input / 6 Relay Output Module – Modbus RTU

From £197.00 (exc. VAT)

2 options available

Advantech ADAM-4150 Series

RS-485 to 15 Channel Digital I/O Module – Modbus

From £128.00 (exc. VAT)

3 options available

Advantech ADAM-4017+ Series

RS-485 to 8 Channel Analog Input Module

From £158.00 (exc. VAT)

1 option available

Advantech ADAM-4069 Series

RS-485 to 8 Channel Power Relay Output Module – Modbus

From £171.50 (exc. VAT)

1 option available

Advantech ADAM-4068 Series

RS-485 to 8 Channel Relay Output Module – Modbus

From £133.50 (exc. VAT)

1 option available

Advantech ADAM-4051 Series

RS-485 to 16 Channel Isolated Digital Input Module – Modbus

From £114.50 (exc. VAT)

1 option available

Advantech ADAM-4055 Series

RS-485 to 16 Channel Isolated Digital I/O Module – Modbus

From £119.50 (exc. VAT)

1 option available

Advantech ADAM-4115 Series

Robust RS-485 to 6 Channel RTD Input Module

From £308.50 (exc. VAT)

1 option available

Advantech ADAM-4117 Series

RS-485 to 8 Channel Analog Input Module – Modbus – Extended Wide Temperature Operation

From £229.00 (exc. VAT)

1 option available

Advantech ADAM-4118 Series

RS-485 to 8-Channelannel Thermocouple Input Module – Modbus

From £244.00 (exc. VAT)

Advantech ADAM-4017 Series

RS-485 to 8 Channel Analog Input Module

1 option available

Advantech ADAM-4019+ Series

RS-485 to 8 Channel Universal Analog Input Module – Modbus

From £330.00 (exc. VAT)

1 option available

Advantech ADAM-4024 Series

RS-485 to 4 Channel Analog Output Module – Modbus

From £224.00 (exc. VAT)

1 option available

Advantech ADAM-4168 Series

RS-485 to 8 Channel Reed Relay Output Module – Modbus

From £141.00 (exc. VAT)

1 option available

Advantech ADAM-4080 Series

RS-485 to 2 Channel Counter/Frequency Module

From £147.50 (exc. VAT)

1 option available

Advantech ADAM-4060 Series

RS-485 to 4 Channel Relay Output Module

From £115.50 (exc. VAT)

1 option available

Advantech ADAM-4056SO Series

RS-485 to 12 Channel Isolated Sourcing Digital Output Module – Modbus

From £126.00 (exc. VAT)

1 option available

Advantech ADAM-4053 Series

RS-485 to 16 Channel Digital Input Module

From £106.00 (exc. VAT)

1 option available

Advantech ADAM-4052 Series

RS-485 to 8 Channel Isolated Digital Input Module

From £90.50 (exc. VAT)

1 option available

Advantech ADAM-4050 Series

RS-485 to 16 Channel Digital I/O Module

From £90.00 (exc. VAT)

1 option available

Advantech ADAM-4021 Series

RS-485 to 1 Channel Analog Output Module

From £154.00 (exc. VAT)

1 option available

Advantech ADAM-4018+ Series

RS-485 to 8 Channel Thermocouple Input Module – Modbus

From £279.50 (exc. VAT)

1 option available

Advantech ADAM-4015 Series

RS-485 to 6 Channel RTD Input Module – Modbus

From £275.50 (exc. VAT)

1 option available

Sealevel 540S Series

RS-232 Modbus RTU to 32 Open-Collector Output Adapter

From £378.00 (exc. VAT)

1 option available

Sealevel 540M Series

RS-485 Modbus RTU to 32 Open-Collector Output Adapter

From £378.00 (exc. VAT)

1 option available

Sealevel 530S Series

RS-232 Modbus RTU to 16 Isolated Digital Input/16 Open-Collector Output Adapter

From £428.50 (exc. VAT)

1 option available

Sealevel 520S Series

RS-232 Modbus RTU to 8 Isolated Digital Input/8 High Current Form C Relay Output Adapter

From £280.00 (exc. VAT)

1 option available

Sealevel 530M Series

RS-485 Modbus RTU to 16 Isolated Digital Input/16 Open-Collector Output Adapter

From £428.50 (exc. VAT)

1 option available

Sealevel 520M Series

RS-485 Modbus RTU to 8 Isolated Digital Input/8 High Current Form C Relay Output Adapter

From £280.00 (exc. VAT)

1 option available

Sealevel 463M Series

RS-485 Modbus RTU to 96 Channel TTL Digital I/O Adapter

From £264.50 (exc. VAT)

1 option available

Sealevel 463S Series

RS-232 Modbus RTU to 96 Channel TTL Digital I/O Adapter

From £283.00 (exc. VAT)

2 options available

Sealevel 462M Series

RS-485 Modbus RTU to 96 Channel TTL DB78F Digital I/O Adapter

From £324.00 (exc. VAT)

1 option available

Sealevel 450S Series

RS-232 Modbus RTU to 16 Form C Relay Output Adapter

From £280.00 (exc. VAT)

2 options available

Sealevel 462S Series

RS-232 Modbus RTU to 96 Channel TTL DB78F Digital I/O Adapter

From £368.00 (exc. VAT)

1 option available

Sealevel 450M Series

RS-485 Modbus RTU to 16 Form C Relay Output Adapter

From £280.00 (exc. VAT)

1 option available

Sealevel 420M Series

RS-485 Modbus RTU to 16 Isolated Digital Input/8 Form C Relay Output Adapter

From £266.50 (exc. VAT)

1 option available

Sealevel 420S Series

RS-232 Modbus RTU to 16 Isolated Digital Input/8 Form C Relay Output Adapter

From £266.50 (exc. VAT)

1 option available

Sealevel 410S Series

RS-232 Modbus RTU to 16 Isolated Digital Input/16 Reed Relay Output Adapter

From £254.50 (exc. VAT)

1 option available

Sealevel 410M Series

RS-485 Modbus RTU to 16 Isolated Digital Input/16 Reed Relay Output Adapter

From £254.50 (exc. VAT)

1 option available

Sealevel 440S Series

RS-232 Modbus RTU to 32 Reed Relay Output Adapter

From £304.50 (exc. VAT)

1 option available

Sealevel 440M Series

RS-485 Modbus RTU to 32 Reed Relay Output Adapter

From £304.50 (exc. VAT)

1 option available

Sealevel 430S Series

RS-232 Modbus RTU to 32 Isolated Digital Input Adapter

From £230.00 (exc. VAT)

1 option available

Sealevel 430M Series

RS-232 Modbus RTU to 32 Isolated Digital Input Adapter

From £230.00 (exc. VAT)

1 option available

Sealevel 470M Series

RS-485 Modbus RTU to 16 Analog Input/2 Analog Output – 8 Isolated Digital Input/8 Digital Output Adapter

From £465.50 (exc. VAT)

1 option available

Sealevel 470S Series

RS-232 Modbus RTU to 16 Analog Input/2 Analog Output – 8 Isolated Digital Input/8 Digital Output Adapter

From £465.50 (exc. VAT)

1 option available

Sealevel 570M Series

RS-485 Modbus RTU to 8 Analog Input – 8 Isolated Digital Input/8 Form C Relay Output Adapter

From £403.00 (exc. VAT)

1 option available

Sealevel 570S Series

RS-232 Modbus RTU to 8 x 16-bit Analog Input – 8 Isolated Digital Input/8 Form C Relay Output Adapter

From £403.00 (exc. VAT)

1 option available

Sealevel 540S-OEM Series

RS-232 Modbus RTU to 32 Open-Collector Output OEM Board

From £366.00 (exc. VAT)

1 option available

Sealevel 540M-OEM Series

RS-485 Modbus RTU to 32 Open-Collector Output OEM Board

From £366.00 (exc. VAT)

1 option available

Sealevel 530S-OEM Series

RS-232 Modbus RTU to 16 Isolated Digital Input/16 Open-Collector Output OEM Board

From £415.00 (exc. VAT)

1 option available

Sealevel 530M-OEM Series

RS-485 Modbus RTU to 16 Isolated Digital Input/16 Open-Collector Output OEM Board

From £415.00 (exc. VAT)

1 option available

Sealevel 520S-OEM Series

RS-232 Modbus RTU to 8 Isolated Digital Input/8 High Current Form C Relay Output OEM Board

From £266.50 (exc. VAT)

1 option available

Sealevel 520M-OEM Series

RS-485 Modbus RTU to 8 Isolated Digital Input/8 High Current Form C Relay Output OEM Board

From £266.50 (exc. VAT)

1 option available

Sealevel 463S-OEM Series

RS-232 Modbus RTU to 96 Channel TTL Digital I/O OEM Board

From £257.50 (exc. VAT)

1 option available

Sealevel 463M-OEM Series

RS-485 Modbus RTU to 96 Channel TTL Digital I/O OEM Board

From £239.00 (exc. VAT)

1 option available

Sealevel 462S-OEM Series

RS-232 Modbus RTU to 96 Channel TTL DB78F Digital I/O OEM Board

From £340.50 (exc. VAT)

Showing 60 of 73

Why Use Serial I/O When Ethernet Is Available?
Serial modules are simpler and often more predictable in environments with electrical noise. They suit applications where deterministic communication and minimal overhead matter more than bandwidth.

What Should You Consider for RS-485 Systems?
Check the maximum number of nodes per bus and whether termination resistors are built-in. Correct line balancing is key to keeping communication stable over long runs.

How Do They Fit into Mixed Networks?
Many serial I/O modules can be paired with protocol gateways, extending the life of older installations by linking them to modern supervisory systems.