User manual

21 Chapter 2
If a jumper is set to "ON," the driver is always enabled, and always in
high or low status. The user must select a mode before beginning RS-422
applications.
Figure 2.15: Enable Mode Selection for PCL-743B/S, PCL-745B/S and
PCL-846A/B
PCL-746+
Should you wish to configure the PCL-746+ to operate in the RS-232
mode, then the upper two pins of the 12*3 pin jumper should be con-
nected. For RS-422/ RS-485 mode selection, the bottom two pins of the
12*3 pin jumper should be connected as shown below.
Figure 2.16: RS-232/422/485 Mode selection for PCL-746+
For either RS-422 or RS-485 mode selection the 1*3 pin jumpers for each
port have to be configured. For RS-422 configuration the upper two pins
of the 3-pin jumper should be connected. A 2-pin jumper is used for Tx
control. Closing the jumper initiates Tx automatic flow control. An open
jumper means that Tx is always on. For RS-485 configuration the bottom
two pins of the 3-pin jumper should be connected and the 2-pin jumper is
always closed as shown below.