Serial interface RS422/RS485 KL6021
Top view 
Contact assembly 
extended shock and vibration range

KL6021 | Serial interface RS422/RS485

The KL6021 serial interface allows devices with an RS422 or RS485 interface to be connected. The device connected to the terminal communicates with the automation device via the Bus Coupler. The active communication channel operates independently of the higher-level bus system in full or half duplex mode at up to 19,200 baud. The transmission of differential signals conforms to RS422 and guarantees high immunity to interference through electrically isolated signals.

Technical data KL6021 | KS6021
Technology RS422/RS485
Data transfer channels TxD and RxD, full/half duplex
Data transfer rates 1200…19,200 baud; default: 9600 baud, 8 data bits, no parity and one stop bit
Bit transfer with differential signal
Line impedance 120 Ω
Cable length approx. 1000 m twisted pair
Power supply via the K-bus
Current consumption K-bus typ. 65 mA
Current consumption power contacts – (no power contacts)
Electrical isolation 500 V (K-bus/signal voltage)
Data buffer 128 bytes receive buffer, 16 bytes transmit buffer
Bit width in the process image input/output: 3 x 8 bit user data, 1 x 8 bit control/status (up to 5 x 8 bit user data are possible)
Configuration no address setting, configuration via Bus Coupler or controller
Special features high interference immunity, electrically isolated signals
Weight approx. 60 g
Operating/storage temperature 0…+55 °C/-25…+85 °C
Relative humidity 95 %, no condensation
Vibration/shock resistance conforms to EN 60068-2-6/EN 60068-2-27
EMC immunity/emission conforms to EN 61000-6-2/EN 61000-6-4
Protect. class/installation pos. IP 20/variable
Pluggable wiring for all KSxxxx Bus Terminals
Approvals CE, UL, Ex
Special terminals
KL6021-0020 standard format 5 bytes of user data (rest default)
KL6021-0021 standard format 5 bytes of user data (7 bits, even, 1 stop bit, 9600 baud)
KL6021-0023 serial Bus Terminal for processing the RS485 signals from the KL6023 wireless adapter with EnOcean radio technology
TS6340 IEC 61131-3 software library for TwinCAT PLC for communication via serial devices
TS6341 license for using the software library for communication via serial Bus Terminals or PC COM ports using the protocol 3964R/RK512
TS6255 IEC 61131-3 software library for TwinCAT PLC with Modbus RTU function blocks for serial communication with Modbus devices
RS485 For further RS485 products please see the system overview.