Raypak VERSA IC, Инструкция по установке и эксплуатации

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4. MODBUS = RATE (Rate Control Mode)
a. The VERSA IC
®
Control operates as a slave
to a Modbus master control (See table AA).
i. Operates as a single-boiler only (no cas-
cade)
ii. Pumps are turned on and off according to
the pump operation sent by the Modbus
master control
iii. No system sensor is required. The boiler
is operated at the target rate sent by the
Modbus master control
1.- A 1 to 100 integer value correspond to
a target firing rate from min+1 to
100%. Do not use negative integer
values.
To enable Modbus with the VERSA IC
®
Control, you
must first turn DIP switch #1 on the VERSA
®
Control
Board to the “ON” position to access the Advanced
menus. The lock icon on the upper right-hand corner
of the VIEW menu will disappear when configured cor-
rectly. From the VIEW menu press the MENU button
once to reach the SETUP menu. Using the ITEM but-
ton scroll to the Modbus MODE screen and select
either MNTR , TEMP or RATE for the functionality
desired. From there press the ITEM button to move to
the ADDRESS screen, DATA TYPE screen, BAUD
RATE screen and then PARITY screen to complete
setup for Modbus.
Modbus Communication
Values
The VERSA IC
®
Control has a setting called Modbus
that determines how it operates when a external con-
troller using the Modbus protocol is connected, the
available settings are:
1. MODBUS = OFF
a. Modbus messages are ignored.
2. MODBUS = MNTR (Monitor Mode)
a. The VERSA IC
®
Control operates as usual,
however the Modbus connection allows for
remote viewing and adjustment of selected
VERSA IC
®
Control parameters (See table
AA).
3. MODBUS = TEMP (Temperature Control Mode)
a. The VERSA IC
®
Control operates as a slave
to a Modbus master control. The Modbus
handles all monitor functions and operates the
boilers, writing the Target Temp, Sys Pump
and DHW Pump data.
i. DHW and System Pumps are exclusively
turned on and off according to the pump
operation sent by the Modbus master con-
trol (See table AA). The VERSA
®
control
board does not control these pump out-
puts in this mode.
ii. Boiler pumps are operated as per usual
by the VERSA IC
®
Control.
iii. The boiler system is operated at the target
temperature sent by the Modbus master
control.
1. A non-zero 1 value below target min
will be interpreted as target min value.
2. A zero value will disable the unit.
3. Values within target min and max
range will call for heat whenever the
supply sensor reading is below target.