Product manual

PX Range Product Manual Version 2.0 © Copyright Brainboxes Limited 2010 Page 20 of 37
These settings are especially helpful when CTS and DSR are not physically connected (such as in a 3
wire setup) and it is not acceptable for the data flow to stop and start due to arbitrary variances on the
unconnected signal lines.
3.4. RS422/485 Settings
For RS422/485 products only, there is an additional tab in the Advanced Settings to allow you to change
duplex mode.
• The drop down list allows users to choose the desired RS422/485 operations mode.
• Select “RS422 full duplex mode” for Full Duplex communications.
• Select “RS485 half duplex autogating mode” for Half Duplex communications.
• For further details on wiring, see Section 8.2: Device Pinout
• Restore Defaults: Pressing this button will reset all settings on this Property Page back to the factory
defaults of this device. The default settings for this Property Page are “RS422 full duplex mode”.
Background Information:
• DTR/DSR Handshaking is not available on 422/485 devices.
• Full Duplex Mode
This mode is generally used between one transmitter / receiver to only one other transmitter /
receiver, but it is possible for each output to drive up to 10 receivers.
Generally, in RS422 systems, all 8 signal lines from the 9 pin D connector participate in the data
transfer sequence. Thus 4 twisted pair cables are used. One twisted pair carries the TXD data
outwards, one pair brings the RXD data inward, another pair carries the RTS handshaking signal