PureFire PFA-1 Interface Adaptor Installation, Operation, and Maintenance Manual

4
Table 3
PUREFIRE PFA-1 INTERFACE ADAPTER
Table 4
Control State Descriptions
STATE
State Name Description
Decimal Hexadecimal
0 0x00 RESET_0 Initialization
1 0x01 RESET_1 Initialization
2 0x02 STANDBY_0 Standby waiting for heat demand
3 0x03 SAFETY_ON Ignition Sequence
4 0x04 SAFETY_OFF Ignition Sequence
5 0x05 PRE_PURGE Ignition Sequence
6 0x06 PRE_PURGE_1 Ignition Sequence
7 0x07 IGNIT_0 Ignition Sequence
8 0x08 IGNIT_1 Ignition Sequence
9 0x09 BURN_0 Following Boiler Demand
10 0x0A POST_PURGE_0 Purging Combustion Chamber
11 0x0B POST_PURGE_1 Purging Combustion Chamber
12 0x0C PUMP_CH_0 Following CH Demand w/o Heat Input
13 0x0D PUMP_CH_1 Post Purge Pumping after CH Demand
14 0x0E PUMP_HW_0 Following DHW Demand w/o Heat Input
15 0x0F PUMP_HW_1 Post Purge Pumping after DHW Demand
16 0x10 ALARM_1 Error Handling
17 0x11 ERROR_CHECK Error Handling
18 0x12 BURNER_BOOT Controller (re)start
19 0x13 CLEAR_E2PROM_ERROR Error Handling
20 0x14 STORE_BLOCK_ERROR Error Handling
21 0x15 WAIT_A_SECOND Error Handling
The following example describes how to read the temperature holding registers (byte 4-7 and 14-15). The boiler supply and return
temperatures can be read by issuing a Modbus command to read holding register “0x0004”. If the word value returned is
“0x1D17”, then we know that the high byte is “0x1D” and the low byte is “0x17”. Converting 1D to decimal, we get 29. Using
the formula above to convert to degrees Celsius we get, 4.5°C (40°F). Similarly, the return temperature is found by converting the
hexadecimal 17 to decimal 23. Using the formula above, this is equivalent to 1.5°C (35°F).
Control Status Descriptions
STATUS
Status Name Description
Decimal Hexadecimal
0 0x00 STANDBY Standby waiting for Heat Demand
14 0x0E BLOCK Error Handling
10 0x0A ALARM Error Handling
15 0x0F FROST_PROTECT Freeze Protection Demand
16 0x10 CH Central Heating Demand
17 0x11 RESET_STATE Initializing
18 0x12 STORAGE DHW Demand
19 0x13 Not Applicable Not Applicable
20 0x14 Not Applicable Not Applicable
21 0x15 STORE_WARM_HOLD DHW Demand (Store Warm Hold)