User`s guide

Chapter 6 Special Features: Software Selectable MEI 61
This chapter describes configuring MEI (Multiple Electrical Interface)
settings through the web interface for the PortServer TS 8 MEI* and
PortServer TS 16 MEI*. The internal MEI settings are switched to EIA-232
by default.
*Except for the PortServer TS 8 MEI and PortServer TS 16 MEI devices,
the remaining Digi TS Family have external DIP switches for MEI settings.
About MEI Settings
PortServer TS 8/16 MEI devices are shipped with the ports switched to
EIA-232 by default. The 232 drivers will generate voltages of 6V max. This
voltage is well within the tolerances of EIA 422/485. The 232 drivers are
current limited so they can’t over-drive another EIA-422/485 output and
damage their devices.
The same engineering applies if a port is set at EIA-422 and a 232 device
is connected to it. The voltage generated is within the tolerance of the
serial device and will not damage either device.
In either case, your serial device may or may not produce ‘data chatter’ -
that is, text strings that have no meaning. This is an indication that the MEI
settings are not in agreement and should be configured.
If there is a loss of power to the unit, the device will not lose the MEI
configuration. After it boots up, it will recall and apply the last MEI settings.
Configure the MEI Switches
1. Log into the Digi PortServer TS
2. Click Serial Ports > port #
3. Select your port profile for your environment and click Apply.
4. Click MEI Serial Settings
5. Select the Tx Control setting for your scenario.
Chapter 6
Special Features: Software Selectable
MEI