User`s manual

EM1500 User’s Manual www.rabbit.com 47
5.1.5 Serial Tab for RS485
The RS485 serial port does not have hardware handshaking lines, so can not use any of the flow control
methods. However, since it is half-duplex, a transmitter enable discipline is defined.
Figure 5.6 Serial Tab for RS485
Tx Enable
Transmitter enable control used for half-duplex RS485. The choices are:
• None
• Rx Idle
Rx idle time (char times)
If “Rx Idle” was chosen for transmitter enable control, this parameter specifies the
time interval which Rx must be idle before the unit can enable the transmitter.
The relay configuration parameters are the same for the RS-485 port as they are for the other serial ports.