Hioki DSM-8542, Instruction Manual, Page: 121 / 140

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8. RS-232 Interface
8.1 Overview
The DSM-8542 features an RS-232 interface option as a communication function.
Basically, the data format and program messages of the RS-232 interface are the same
as those of the GP-IB interface, except some messages and other parts that are required
due to differences in the hardware. This chapter describes only the differences with the
GP-IB interface. For the other parts, the reader is requested to refer to Chapter 7
“GP-IB Interface.”
8.2
Connector Used and Signal Names
The connector for the RS-232 interface is a 9-pin D-sub female connector.
Table 8.1 Pin Nos. and Signal Names
Pin No. Signal
Name
Function Remarks
1 DCD Reception carrier detection Not used with
DSM-8542
2 RXD Reception data
3 TXD Transmission data
4 DTR Data terminal ready
5 GND Signal ground
6 DSR Data setting ready Not used with
DSM-8542
7 RTS Transmission request
8 CTS Transmission authorized
9 RI Incoming call indication Not used with
DSM-8542
8.3
Changeover to GP-IB
GP-IB and RS-232 cannot be used simultaneously. The GP-IB or RS-232 interface
whichever accepts a message first is selected as an interface.
When changing the interface, temporarily reset to the local mode or turn the power
supply on again.
8.4
Connecting Control Signals and Flow Control
The flow of data transmission and reception is controlled in the DSM-8542 by controlling
the RTS signal. Control the controller in the Terminal mode by connecting as follows.