Specifications

12 PCL-741 User's Manual
Protocol Selection
Firstly you have to decide which mode each port will be operating in,
RS-232 or current-loop driver mode. You can configure each port to
operate in a different mode if required. Each port has to be individu-
alIy set-up by selecting the correct jumper configurations on the
three jumper groups identified as CH1 and CH2, these consist of a
10*3 pin jumper, a 2*3 pin jumper and a 1*3 jumper.
RS-232 Mode Selection
For RS-232 mode operation the jumpers will be set as in the default
mode. The jumpers on the 10*3 pin jumper must be set to the upper
position.
Note: When either channel is configured in the RS-232
mode the two associated TxlRx active/passive
jumpers are inoperable.
Current-Loop Mode
Should you want to configure the PCL-741 to operate in the current
loop mode then configure the main jumper so the jumpers are in the
lower position. Then decide which mode the Tx and Rx will operate
in. The options are active or passive. In the active mode the Tx or Rx
will generate the current required for data transfer over the link. In
the passive mode the current is generated by the card at the other end
of the link.