System information

12

It is suggested that polling intervals not be less than 200 mSec per request. Requesting data
such as burner minutes, system minutes and burner cycles should be kept at a minimum due to
the amount of processing time required to gather that data.
Messages 00, 05, 08, 10, 15, 21 and 26 are unique in that a limited number of successive registers can
be combined with these requests. For example, a request to message 00 can contain up to 6 data
words. The response to this would contain STATUS, MSGN, GSTAT, TIMER, FLAME and
LOGSTAT. If the requested data word count (DAT) were to be 2 then the response would contain
STATUS and MSGN only. Message 15, last 6 lockouts, can return data ranging from 1 to 6, with 1
referring to the most recent lockout.
The MSGN being transmitted is a numerical value and must be interpreted by the communicating
device, which actually is an advantage since this can be made to be whatever message text the end
user wants. In other words, it allows for programming custom messages without actually changing
the message in the programmer. Refer to Table 4 for message information.
Message 26 returns the current operating status as well as stored burner hours and burner cycles as a
snapshot of the entire Flame-Monitor system. When all 9 words are requested, the data returned con-
sists of STATUS, MSGN, FLAME, INPUTS, OUTPUTS, BNRMINS, and BNRCYCS
The Flame-Monitor stores its burner on time and system on time (L1 powered) in minutes. For dis-
play purposes, the programmer converts this to hours. The information being supplied by Modbus
will be the actual time in minutes and it is up to the communicating device to do the conversion.
Since the maximum value stored in the Flame-Monitor is 9,999,999 minutes, the maximum value in
hex therefore is 98967FH and comprises two data words. The maximum cycle count is 999,999 dec-
imal or F423FH, still two data words. As an example, the System on Minutes data is transmitted from
the Flame-Monitor to the interface as high word / low word as shown below:
Note: Data from address 9 cannot be accessed directly.
MESSAGE
ADDRESS
WORD
REQUESTED
RESPONSE VALUE
23 Not Used
24 2 FLAME SIGNAL
AVERAGES
PTFI and Auto Flame Signal Averages
26 1-9 Combined status See Description Below
35 6 Most Recent
Lockout Data
Returns complete lockout description of stored lockout history.
Includes lockout message, lockout module, @ burner hours, and
@ burner cycles
41 6 2nd Most Recent Lock-
out Data
47 6 3rd Most Recent
Lockout Data
53 6 4th Most Recent
Lockout Data
59 6 5th Most Recent
Lockout Data
65 6 6th Most Recent
Lockout Data
71 1-3 Input limits and Expan-
sion Module registers
Returns input limits state and lower and upper expansion mod-
ule (E300) registers. See Table 3
72 1-2 Expansion Module
(E300) registers
Returns lower and upper Expansion module registers
73 1 Return only upper Expansion module register
Address 8 Address 9
High Word Low Word
High Byte Low Byte High Byte Low Byte
0 98H 97H 7FH