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Programmable ControllerKV-8000 series

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



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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 specification

Electrical termination (Terminator)

ON / OFF set by the switch on the front face

Transmission rate

1,200, 2,400, 4,800, 9,600, 19,200, 38,400, 57,600, 115,200, 230,400 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 or 8 bits
Stop bit: 1 or 2 bits

Error detection

Parity: Even, odd, none

RS/CS flow control

ON or OFF(only in PLC link mode)

Transmission distance

Total extension: 1,200 m max.*2*3

Number of transmission units


Connectable CPU units

KV-7500 / 7300


Automatic refresh, direct refresh,inter-unit synchronisation refresh

Serial communication functions

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

Serial communication function execution methods

Ladder program, unit program (flow)

Unit program capacity

3 MB (max. number of blocks: approx. 20,000)


Maximum number of flows


Number of simultaneous activities


Internal data memory

524,288 words


Transmission method

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

Maximum number of connected devices


Maximum number of communication commands

48 / 96*4

Maximum number of total frames

Rx: 48 / 96*4 × 16;
Tx: 48 / 96*4 × 1

Maximum number of compared and receive frames

16 per command

Maximum number of block elements

96 per frame

Transmission data length

1 to 2,048 bytes per frame

Received data length

PLC link

Communication patterns

Write, read, transfer

Number of link settings

512 settings max.*5

Link data size

1,440 words max. per setting (bit: 720 words, word: 720 words)
737,280 words max. (total)(1,440 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*5)

Update interval

10 to 65,535 ms

Internal current consumption

150 mA or less


Approx. 190 g

*1 For KV-8000/KV-7000 Series
*2 Depends on the function to be used.
*3 The total extension is 500 m max. at a transmission rate of 230,400 bps. The transmission rate and distance vary depending on the device to be connected. Check the values according to the actual device.
*4 The max. is 48 when “Standard” is set for the number of communication commands on the Unit Editor and 96 when “Extended” is set.
*5 Total for one KV-XL202 / XL402 unit.

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