User`s guide

Four-Wire Multi-Drop Network Scenarios
78 Chapter 6 Configure MEI Settings
Set the Supported Baud Rate for Multi-drop Support
The PortServer TS 8/16 MEI requires setting a baud rate range in order to
perform the automatic transmitter control. This setting does not influence
the performance in EIA-232 mode or for EIA-422/485 configurations where
the transmitter is always on.
The range supported by default is: 50 -230400 bps
To change the supported baud rate range
1. Select System > MEI.
2. From the Baud Rate drop-down box, select the appropriate baud rate.
3. Select Enable all serial ports (to enable the serial port transmitter) if
appropriate.
4. Click Apply for configuration to take effect.
Four-Wire Multi-Drop Network Scenarios
There are two scenarios of devices on a four-wire multi-drop network: the
Master and the Slave. A Master has a dedicated pair of wires to talk to the
Slaves. The Slaves share a return pair to the Master and need to control
their transmitters so that only one device at a time uses that pair. Following
are the specific procedures to set up a Master or Slave MEI setting.
MEI Configuration for a Single Master:
1. Click Serial Ports > port # > MEI Serial Settings.
2. Select 422/485, Tx Control > Always on.
3. Select Enable alternative pinout (altpin). This option is only enabled
with 4 Wire. See the Table for Pin Outs for more information.
4. Click Apply for settings to take effect.
MEI Configuration for a Slave:
1. Click Serial Ports > port # > MEI Serial Settings.
2. Select 422/485, Tx Control > Auto.
3. Select Enable alternative pinout (altpin). This option is only enabled
with 4 wire. See the "MEI Configuration for a Slave:" on page 78 for
more information.
4. Click Apply for settings to take effect.
Note: You do not need to reboot after you click Apply for MEI settings to take effect.