Connecting a 9-way socket to the SDM‑SIO2R for RS-232 devices

This configuration may be used if the device is fitted with a standard 9-way D connector as was commonly fitted to computers for their RS-232 port. You need to check whether the device is configured as a DTE or DCE device and whether it has a male or female connector before making up this cable.

• In RS-232 mode, the main use of the CTS/RD– and RTS/TD+ lines is as RTS/CTS hardware handshaking lines. CTS/RD– should be connected to the remote equipment RTS and RTS/TD+ to its CTS line.

• The CTS/RD– (CTS) and RTS/TD+ (RTS) lines can also be used to trigger external circuitry when not being used in handshaking mode.

  NOTE:

  When using CTS/RD– and RT/TD+ lines as input and output, the voltage levels are ±5V, NOT 0 and 5V.

• CTS/RD– and RTS/TD+ cannot be used as separate input and output when in RS-485 mode.