KL6031, KL6041 - Serial interface terminals

KL6041 – Basic function principles

The KL6041 serial interface terminal enables the connection either

of devices with an RS485 interface or
of a device with an RS422 interface (peer to peer).

Depending on the higher-level fieldbus system, data can be exchanged with the controller in full-duplex or half-duplex mode. The size of the receive buffer is 1024 bytes, that of the transmit buffer 128 bytes. The data transfer between terminal and controller is handled via a handshake in the status and control byte. The factory setting of the terminal is 9600 bit, 8 data bits, 1 stop bit, no parity, full duplex mode.


LED display

The Run LED indicates the operating state of the terminal.
On – normal operation
Off – Watchdog timer overflow has occurred. If no process data is transmitted from the Bus Coupler for 100 ms, the green LED goes out.

The TxD and RxD LEDs indicate the states of the signal lines.


Process data - standard output format

In the standard output format, 22 bytes of user data and 1 Control/Status word are mapped in the Bus Coupler. By changing the parameters of the KL6041, up to 3 or 5 bytes of user data can be transmitted.


Connection for RS485 transfer

In RS485 mode, data are exchanged in half duplex mode. A bus structure can be created in this operation mode.


Connection for RS422 transfer

The data are transmitted in full duplex in the RS422 operation mode. Only peer-to-peer connections can be established.



The chapter on Access from the user program contains an overview of possible mapping configurations, depending on the configurable parameters.