Interface Setup | GPIB Interface
RS232C Interface | USB Interface

RS232C Interface

RS232C connection

Turn off the POWER switch on the KFM2150 and the controller.

Use a D-sub 9-pin female-to-female AT type cross cable for the RS232C cable. Fig. 1 shows the connector pin assignments.

Because the KFM2150 does not use hardware handshaking (Cross cable example2).


Fig.1    9-pin AT type connector

RS232C configuration

1.      Check that the load is turned off.

2.      Press the MENU key.
The MENU screen appears.

3.      Press the , , and arrow keys to select Configuration > Interface > TYPE and turn the rotary knob to select RS232C.

4.      Press the or arrow key to select Baudrate, and turn the rotary knob to set the baud rate.

5.      Likewise, set Data, Stop, Parity, and Ack.

6.      Press the MENU key.
The MENU screen closes.

7.      Turn the POWER switch off and then turn it back on.
The settings are applied.


Table 2 shows the RS232C protocol.

Underline indicates factory default condition.


Table 2    RS232C protocolI

Item Setting
Connector 9-pin D-sub terminal on the rear panel
Baudrate 2 400 bps/ 4 800 bps/ 9 600 bps/ 19 200 bps
Data length 7 bits or 8 bits
Stop bit 1 bit or 2 bits
Parity Fixed to none
XON/XOFF control ON/ OFF

Break signal

The break signal functions as a substitute for the IEEE488.1 dcl/sdc (Device Clear, Selected Device Clear) message.

RS232C communication

Use X-Flow control or acknowledge function for RS232C communication.

Transmission/reception may not work correctly through unilateral transmission.

- X-Flow control

The transmission/reception on the KFM2150 can be controlled using Xon/Xoff. DC (device control) codes are used as control codes.

Table 3    DC codes

Code Function ASCII Code
DC1 Transmission request 11H
DC3 Transmission stop request 13H


Fig.2    RS232C terminal and transmission control of the KFM2150

- Acknowledge message

An acknowledge message is information sent from the KFM2150 to the controller. It notifies that the processing of the program message has been completed.

The acknowledge message is an ASCII code string consisting of only the header. The following two types are available.

• OK: Normal completion

• ERROR: Error such as a syntax error or query error

To use acknowledge messages, set Ack to On in the CONFIG settings.

On the controller, the RS232C configuration must be set to full-duplex operation.