17.4 Specific Modbus function groups
17.4.1 CustomLogic: Modbus signal
You can find the function group
CustomLogic: Modbus signal
in the Discrete output coil (01; 05; 15) and the Discrete input contact
(02) sheets of the Modbus table. The function group allows you to interact with the CustomLogic of the controller using Modbus.
When you read a value from these addresses, the controller will return a value to show if the flag for the signal is active (true, 1) or
not active (false, 0). When you write a value to the addresses in the Discrete output coil, the value stored in the address changes to
the new value.
INFO
You cannot write values to Modbus signals that have been assigned to coils in CustomLogic.
More information
See
CustomLogic, Modbus
in the
PICUS manual
for examples of how to assign a Modbus signal to CustomLogic
elements.
17.4.2 Breaker priority: Buffered value
Overview
You can find the function group
Breaker priority: Buffered value
in the Holding register of the Modbus table. The function group acts
as a temporary storage area for the breaker priority values that will be written to the controller using the function group
Breaker
priority: Write values
.
When you read a value from these addresses, the breaker priority that you want to assign to the breaker that is stored in the
address is returned to you. When you write a value to these addresses, the value is stored and ready to be written to the controller
when you activate
Breaker priority: Write values
.
CAUTION
The breaker priorities and the Modbus address associated to a specific breaker is dependent on the
Single line
configuration. If you change the
Single line
configuration, you will change the associated Modbus addresses. If you add or
remove GENSET controllers from the
Single line
configuration, the breaker priorities can change.
Breaker priority allocation
The following rules are applied when breaker priorities are assigned:
•
Only GENSET controllers receive a breaker priority value that is greater than zero (0).
•
All other controller types receive a breaker value of zero (0).
•
An EMERGENCY genset controller uses two Modbus addresses, the first for the tie breaker and the second for the generator
breaker. Both breakers have a breaker priority of zero (0).
•
Breaker priorities are assigned to the first available breaker priority, according to the order in which controllers are added to the
single line diagram.
•
Breaker priority Modbus addresses are assigned to the first available breaker priority Modbus address, according to the order in
which controllers are added to the single line diagram.
DESIGNER'S HANDBOOK 4189340911K UK
Page 481 of 521
