Specifications

Ammonia Gas Monitor – Multi Zone
58 Instruction 3015-5113
Release Service Mode Register Register 0x001Chex 28dec W 10 bytes
Variable Type Length Description
Ent Svc_Mode * * See description of STATUS REGISTER
AGM-MZ Service Mode
The AGM-MZ can be placed into service mode if necessary. During service mode the unit will take no
measurements, any and all alarms are silenced, and all relays are opened. The unit automatically comes out
of service mode after a preset interval defined by the service_mode_TO parameter in the System Data
Register.
Placing the AGM-MZ into Service Mode:
1. Read the AGM-MZ Status Register (0x0011h)
2. Modify the content of the status register structure to change the MODE parameter to service mode.
3. Send this updated status register structure back to the AGM-MZ using PRESET MULTIPLE
REGISTER COMMAND to the SERVICE MODE REGISTER (0x001Bh).
Releasing the unit from Service Mode:
1. Read the AGM-MZ Status Register (0x0011h)
2. Modify the content of the status register to change the MODE parameter to normal mode.
3. Send this updated status register structure back to the AGM-MZ using PRESET MULTIPLE
REGISTER COMMAND to the RELEASE SERVICE MODE REGISTER (0x001Ch).
PPM Register Register 0x001Ehex 30dec R 32 bytes
Variable Type Length Description
PPM UI 32 bytes
16 Unsigned Integers that represent the PPM values for
each AGM-MZ zone
NOTE: 16 values are returned independent of the number of actual zones installed in the unit. The master
device is required to know how many zones are installed in the unit (available in the System Register) in order
to properly interpret the data.
Zone Log Registers Register 0x3xyyh R 1502 bytes
These registers are used to transfer the zone log data. Each zone has a circular log of 100 past data points.
The period between data points is defined by the Log Interval parameter in each corresponding Zone Data
Register. The data for each zone is defined by the “x” place in the above register address. For zone 1 the
Register address is 0x30yyh, for zone 2 the register address is 0x31yyh, etc. The data for each zone is sent
in 8 consecutive registers due to MODBUS RTU message length constrains. The addresses are defined by
the “yy” place in the above address. For zone 1, all log data can be obtained by reading 0x3000h, 0x3001h,
0x3002h, …… , 0x3007h. The first seven registers contain 200 bytes each and the last register contains 102
bytes. After all registers have been received the data should be reassembled into the full data structure.
Variable Type Length Description
Index UI 2 Point to current reading
Time TIM 1300
Time record for each of the 100 log points. The format for
the TIM type is defined in note 2 of zone data
PPM UI 200 Last 100 log points (2 byes per point)