6 • PerformanceAlert Gateway I&O Manual
4.1.2. PerformanceAlert™ Module
MODBUS Addressing
Jumpers AD1 through AD4 on the PerformanceAlert™
module set the MODBUS device address. Modules should
be uniquely numbered in sequence starting with 1 and con-
tinuing in numerical order up to 14. Refer to
jumper settings for each address number.
4.1.3. Gateway MODBUS Wiring
Connect the Gateway to the MODBUS network as
. Connect the BLACK wire to
RS485+, the WHITE wire to RS485-. Connect the
SHIELD wire to the middle (0v) terminal.
For convenience, when the Gateway is not the end of
the daisy-chain, the MODBUS connector has a second set
of terminals.
4.1.4. MODBUS Termination
To minimize network interference on the MODBUS
network, the daisy chain must be terminated at both end-
points, with all devices in between left unterminated. Refer
to the diagram in
for diagrams showing the dai-
sy chain endpoints.
The PerformanceAlert™ module is terminated by plac-
ing a jumper across the TRMNTR pins. The Gateway
board is terminated by setting the three jumpers next to the
MODBUS connector to the TERMINATION setting as
shown in
4.2.
Connecting the Gateway to
the RS485 I/O Network
Connect the RS485 I/O Network wire to the three-ter-
minal connector on the Gateway board as shown in
. For further information about how RS485 networks
are configured, refer to your site controller’s user manual.
Figure 4-3
- PerformanceAlert™ MODBUS Addressing
Figure 4-4
- Gateway Board MODBUS Wiring
Figure 4-5
- MODBUS Termination