PMSTR-4000
Quick Start Tips
September 15, 2021
Page 1
The PMSTR-4000 Plant Master controls up to eight NXF4000 and/or PPC4000 in any
combination using a central sensor. The connection from the PMSTR-4000 is via
Modbus and uses the dedicated sequencing bus.
WIRING
The Modbus terminals for the sequencing bus are on connector P12:
P12.3: Modbus A+
P12.4: Modbus B-
Just as when using peer-to-peer sequencing, all the connected units must be wired in a
serial string, also known as a “daisy-chain”. This means that each control is connected
to the next, and only the first or the last control is connected to the PMSTR-4000.
CONFIGURATION OF UNITS
First, sequencing must be enabled on each NXF4000 or PPC4000. It is also important
that no control is specified to be the master, and that the LEAD LAG key on the keypad
is disabled so that a master isn’t inadvertently specified in the future. If a master does
get enabled on one of the units there will be communication issues from the PMSTR-
4000.
The sequencing bus has communication settings fixed at 19200 baud, eight data bits,
no parity and one stop bit. The node address for the sequencing bus is the same as the
node address used for the BMS Modbus port.
Settings to change on each NXF4000 or PPC4000:
COMMUNICATION SETUP
UNIT ADDRESS
(1-8)
SEQUENCING SETUP
MASTER SLCT
COMMS
SEQUENCING SETUP
SLAVES AVAILABLE
0
KEYPAD SETUP
LEAD LAG KEY
UNUSED
