The N4CRB04 is a multi-functional RS485 I/O module developed and manufactured by eletechsup. In addition to supporting the standard MODBUS RTU protocol, it also has several features not found in older versions, such as a watchdog timer to ensure automatic reset in case of device malfunction, and an input port counting function to ensure no input signals are missed.

The N4CRB04 is a multifunctional product:

1. Compatible with NPN/PNP level inputs
2. Counts input pulses (Registers 0x0020-0x0023)
3. Multiple relay control modes: inching, self-locking, and interlocking
(registers 0x0000-0x0003)
4. Watchdog function (register 0x00F3)
5 Remote IO function (registers 0x00F5-0x00F6)
6 Automatic reporting of digital input(DI) status(register 0x00F8)
7 Input and output relationship（DI-DO relationship）(register 0x00FA)


Features:

1: Operating Voltage: DC 12V/24V
2: Operating Current: Standby current (all relays closed) 12MA, 1 relay open 40MA, 2 relays open 68MA, 3 relays open 93MA,4 relays open 120MA
3: 4ch 3-24V NPN/PNP Opto-Isolated Input Ports
4: The input-output relationship can be set to various association modes through instructions(Self-lockingdefault)/Interlocking/Momentary/Interlocking/Output=Input)
5: The input port can remotely control the output port of another board through the RS485 bus
6: The input port has a counting function. It can count pulses greater than 100MS (the pulse width can be set from 10 to 2000MS).
7: Support standard Modbus RTU command, function code, write 05/06/15/16 read 01/02/03
8: With hardware reset function, with TVS anti-surge protection
9: 4 opto-isolated inputs (NPN), 4 relay outputs (upgraded relays, more durable)
10: MODBUS commands can be made serial HyperTerminal (serial assistant) OR ''Modbus Poll''Enter;
11: Under the MODBUS command mode, it can support up to 254 devices in parallel
12: The default baud rate is 9600BPS. The baud rate can be selected by Conmand 2400 4800 9600 19200 38400 57600 115200BPS
13: The parity can be none parity, even parity and odd parity
14: The data sending and returning time can be set,with a maximum value of 1000ms
15: Size: 73 * 72 * 19mm(Only PCB Board);76 * 82*40mm(with Din Rail Box)
16: Weight: 80g(Only PCB Board);142g(with Din Rail Box)
17: Maximum load: 10A / 250VAC, 10A / 125VAC, 10A / 30VDC, 10A / 28VDC, 10A / 12VDC