Programmable Logic Controller

KV-8000 series

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Serial communication unit, 2 ports (RS-422A/485×2) KV-XL402

KV-XL402 - Serial communication unit, 2 ports (RS-422A/485×2) 

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  • UL Listing(c/us)





Serial communication unit

Communication standard

RS-422A RS-485 (4 wires), RS-422A RS-485 (2 wires)

Connection interface

European terminal block with 5 poles (detachable) × 2 ports

Transmission specifications

Electrical termination (terminator)

ON/OFF set by the switch on the front face

Transmission rate

1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400 bps

Transmission method

RS-422A RS-485 (4 wires): Full duplex
RS-422A RS-485 (2 wires): Half duplex

Data format

Start bit: 1 bit
Data bit: 7 bits, 8 bits
Stop bit: 1 bit, 2 bits

Error detection

Parity: Even, odd, none

RS/CS flow control

ON or OFF (only in PLC link mode)

Transmission distance

Total extension: 1200 m 3937.0' max.*1*2

Number of transmission units



Automatic refresh, direct refresh, inter-unit synchronization refresh

Serial communication functions

Non-procedure, PROTOCOL STUDIO, Modbus slave, etc.

Serial communication function execution methods

Ladder program, unit program (flow)

Unit program capacity

3 MB (Max. number of blocks: Approx. 20000)


Max. number of flows


Number of simultaneous activities



Internal data Memory

524288 words


Transmission method

Cyclic communication: Tx + Rx, Tx only, Rx only
Event communication: Tx + Rx, Tx only, Rx only, Tx + Continuous Rx, Break Tx

Max. number of connected devices


Max. number of communication commands


Maximum number of total frames

Rx: 48/96*3 × 16;
Tx: 48/96*3 × 1

Max. number of compared received frames

16 per command

Maximum number of block elements

96 per frame

Transmission data length

1 to 2048 bytes per frame

Reception data length

PLC link

Communication patterns

Write, read, transfer

Number of link settings

512 settings max.*4

Link data size

1440 words max. per setting (bit: 720 words, word: 720 words)
737280 words max. (total) (1440 words × 512 settings)

Data unit

1 word

Number of connected models

2 models max. (1 model × 2 ports)

Number of connected units

2 max. (1 unit × 2 ports)

Trigger types

Cyclic/event (64 settings max. for event*4)

Update interval

10 to 65535 ms

Internal current consumption

150 mA or less


Approx. 190 g

*1 Depends on the function to be used.
*2 The total extension is 500 m 1640.4' max. at a transmission rate of 230400 bps. The transmission rate and distance vary depending on the device to be connected. Check the values with the actual device.
*3 The max. is 48 when “Standard” is set for the number of communication commands in Unit Editor and 96 when “Extended” is set.
*4 Total for one KV-XL202/XL402 unit.

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