Get Floating Status - 0X45 - Honeywell CM4 Technical Handbook

CM4 Four-Point Continuous Monitor

Get Floating Status - 0x45

This packet returns general information about the slave. It combines
the information of packet 0x37 (Get Point Status) and 0x31 (Get Unit
Status). However, it reports the concentration in IEEE floating-point
format instead of as a scaled integer. Since it provides information
that would otherwise require five interrogations, this should
permit faster polling of slaves on a multidrop RS-485 bus.
Command Packet to Slave:
Command Code (0x45) - 1 byte
Response from Slave:
Command code (0x45) - 1 byte
CM4 date - 2 bytes
CM4 time - 2 bytes
Status - 1 byte
0x01 - in monitor
0x02 - maintenance fault relay activated
0x04 - instrument fault relay activated
0x08 - (1 bit) undefined
0x10 - A new fault has occurred since the last time
packet 0x3D (Get Fault History) was requested.
0x20 - A new alarm has occurred since the last time
packet 0x36 (Get Alarm History) was requested.
0xC0 - (2 bits) undefined
(The 7 byte Point Structure repeats 4 times)
Concentration - 4 byte floating point
Number in PPM
Flow - 2 byte integer in CC/min
Point status - 1 byte
0x01 - point disabled in config
0x02 - point disabled now (It may have become disabled
because of a fault.)
0x04 - point locked out
CM4 Technical Manual
0x08 - low flow
0x30 - (2 bits) concentration summary integer. The meaning
of this field is as follows:
00: 0.0 == Concentration
01: 0.0 < Concentration < AL1
10: AL1 <= Concentration < AL2
11: AL2 <= Concentration
0xC0 - (2 bits) current alarm level
00: no alarm
01: alarm level 1 active
10: alarm level 2 active
(End of Point Structure)
Total size is 34 bytes
Example
The following example is an illustration of the above packet using
serial communication protocol version 2. The address of the slave is
42 (0x2A). Point 1 is in a level 2 alarm, but the gas concentration has
decreased below AL2 and AL1 to 42.2 ppb. The other three points
are reading zero concentration. The instrument fault relay is activated
and point 4 is disabled because of loss of flow. Both the Fault History
and the Alarm History have new entries which have not been read
yet. Point 3 is configured to be disabled via menu function 3.1. All
four flows are near the norm of 180 cc/min except for point 4, which
is 139 cc/min.
Master: 40 2A 00 06 45 4B;
Slave: 40 00 2A 27 45
3D;
3D 2C E2 19
00 00 00 00
00 00 00 00
00 00 00 00
5E;
E-16
inquiry
23 64 66 DA; header, date/time
unit status byte
00 BB 90; point 1 data
00 BD 00; point 2 data
00 C4 03; point 3 data
00 8B 0A; point 4 data
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