User`s guide

Chapter 9 Special Features: Power Over the Serial Ports 83
Serial Power Feature
The Serial Power feature available for the PortServer TS MEI Series and
the PortServer TS W MEI Wireless Series allow the Digi device to power a
serial device (power out) or use a serial device to power the Digi device
(power in). The advantage of this feature is to eliminate an external power
supply.
Power out is available on all ports through Ring Indicator (RI) or Data
Terminal Ready (DTR). Power in is available only through RI and only on
port one (1). The Serial Power feature is active on a specific port when that
port is configured for RS 232 operation.
• The power out budget equals one (1) watt (the total amount of
power available). The available power can be divided in any combi-
nation between the ports but the following rules must be observed:
— RI = 5 volts @ up to 200 mA (max)
— DTR = 9 volts @ up to 100 mA (max)
— You may use DTR or RI as the source of power (power out) on
any port but you may not use both DTR and RI on the same port.
• Pinout information
— RI is pin 1
—DTR is pin 9
• RI signaling is lost when the pin is used for power
Configuring RI Power
RI Power In
Ring Indicator (RI) power in accepts power into the Digi device only on port
one. Power in is available using the RI pin. The Digi device requires power
in the range of 9-30 VDC @ 525mA (max). Ports 2, 3, and 4 can still supply
power to a serial device through the RI or DTR pins for each port. When
using power in through the RI, the external power supplies (both powered
Ethernet and the barrel connector power supply) are inoperative. Altpin will
not work for RI power in.
Chapter 9
Special Features: Power Over the Serial
Ports