SRM8 Serial وحدة ريلاي 8-قناة

SRM8 Serial Relay Module 8-Channel

SRM8 is an 8-channel relay module designed to allow expanding microcontroller I/O pins. SRM8 is based on the 8-bit shift register 74595 IC. It supports 8 output relays while using only three I/Os. SRM8 can be daisy-chained to further extend the outputs to theoretically an infinite number while still using the same three microcontroller I/O pins.

SRM8 module can be supplied from a wide range of voltages (5-ZKEEP0Z). The input control signals are Digital Input (DI), Clock (CK), and Load (LD). Every time the shift register Clock input receives a low to high transition it accepts the data input value to bit0 and shifts the internal register data by one bit. Thus, 8 clock pulses are required to get one-byte data from the microcontroller. Finally, a latch pulse is required to load all internal shift register data to parallel outputs (Relays). This control sequence can be performed using a hardware-implemented SPI or a few lines of written code.

Features

• Supports: 8-channel output relays.
• Protocol: SPI.
• Wide operating voltage range: 5-ZKEEP1Z (two selectable ranges).
• Input signals (TTL): Data Input (DI), Clock (CK), and Load (LD).
• Output signals (TTL): Data Output (DO), Clock (CK), and Load (LD).
• Power-on relay status is OFF (a reset operation is auto-applied up on power on).
• Green LED for power indication.
• Red LED indicator for each output relay.
• Both normal open and normal close terminals are available.
• Reverse polarity protection for power input.
• Input and output signals are available via screw clamp terminals as well as pin headers for flexibility.
• SRM8 module can be daisy-chained to obtain a large number of relay outputs.
• The power connector is duplicated to facilitate the daisy chain board-to-board power connection of up to 16 modules, To connect more SRM8 modules use external wiring.
• Mounting: Four (Ø ZKEEP2Z) mounting holes for easy installation.
• Dimensions: 207 X 45 X ZKEEP3Z.

Specifications

Parameter

Value

Model

SRM8

Channels

8 relay outputs

Control Interface

Serial (74595 shift register) — DI, CK, LD (SPI compatible)

Supply Voltage

Wide range 5–ZKEEP4Z (selectable ranges)

Power Connector

Duplicated for easy daisy-chain power up to 16 modules (board-to-board up to 16)

Indicators

1× green power LED

8× red relay status LEDs

Contact Types

NO and NC terminals provided per channel

Protection

Reverse-polarity protection on power input

Signal Access

Screw-clamp terminals and pin headers for DI/CK/LD/DO

Mounting

4 × ØZKEEP5Z mounting holes

Dimensions

ZKEEP6Z × ZKEEP7Z × ZKEEP8Z

Applications

• Expanding microcontroller or PLC outputs for relay-based switching in automation systems.
• Controlling lamps, solenoids, motors and HVAC or lighting circuits in test rigs and control panels.
• Prototyping and classroom projects where many relay channels are needed with minimal wiring.
• Multi-module installations that require convenient chained expansion and centralized power distribution.
• Any low-voltage control system needing reliable, screw-terminal relay outputs.

Package Contents

• 1× SRM8 Serial Relay Module 8-Channel.