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Prepping for Installation
Establishing Communication Protocol
39
Building Technologies
125-202
06/06/2017
Changing Baud Rate or Communication Mode Using Address
Switches (Between Modbus and BACnet)
This procedure is only required if you are Changing Communication Mode using
ViewPoint (between Modbus and BACnet) fails and the MD-BMS or MD-BMED Power
Meter must be returned to a particular communications protocol and baud rate.
1. Power down the MD-BMS or MD-BMED Power Meter (disconnect all voltage leads
or the USB cable).
2. Set the rotary Address switches to F and F.
3. Power up the meter (connect the black and red voltage leads to power or connect
the USB cable).
4. Set LSB to one of the following communication modes:
LSB Address Switch
Communication Mode
RS-485 LED
COM LED
1
Modbus (Factory Default)
Red On
Off
2
BACnet
Red On
Red On
●
Set MSB to one of the following baud rates:
MSB Address
Switch
Baud Rate
PhaseChek
LED CT1
PhaseChek
LED CT2
Phase Chek
LED CT3
1
9600 (Factory Default)
Off
Off
Green
2
19200
Off
Green
Off
3
38400
Off
Green
Green
4
57600 (Modbus only)
Green
Off
Off
5
76800
Green
Off
Green
6
115200 (Modbus only)
Green
Green
Off
After powering up the MD-BMS or the MD-BMED Power Meter, you will have 10
seconds to make changes. However, every time a rotary switch is changed, the 10-
second timer resets. After 10 seconds of no switch action, the settings take effect, and
the switches revert to the Modbus Address selector if in Modbus mode, or MAC
address if in BACnet mode.
Fail-safe: If all address switches are 0, the meter is placed in Modbus mode at 9600
baud rate. Communication registers can be modified for baud rate and for mode.