RELAY DRIVER
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The number of Morningstar Devices on a Meter Bus network is
limited by power constraints. Table 1 shows the relative power
consumption of each type of Morningstar Device. The Meter
Bus network can support a total load of 60.
Morningstar Device
Meter Bus Load
TriStar
Power (0 load)
TS Local Meter (TS-M)
30
TS Remote Meter (RM)
30
Relay Driver (RD)
10
Table 1. Meter Bus loads
5.2.2 Serial Communications
Serial communication through the 9-pin RS-232 port on the
Relay Module allows the user to program the Relay Driver,
upgrade the firmware, and log data using a PC.
A serial cable is included with the Relay Driver. If the serial
cable has been misplaced, any standard 9-pin male/female
straight-through serial cable may be used.
NOTE:
For developers that need to write custom
software to communicate with the Relay Driver over the
serial port using MODBUS® commands, refer to the
document, Relay Driver Modbus Documentation
.
