Ametek 3050-DO

PN 305725901, Rev YF
Holding Registers
Since the RAM space on the analyzers is limited and not every customer’s DCS\
SCADA\DAS\PLC supports Modbus oating point value transfer, oating point
values that are commonly accessed on a 3050 Analyzer are scaled and con-
verted into integer values to load into Modbus registers for transmission. The
register values need to be scaled back at the receiving end to yield the actual
values. The size of a Modbus holding register is 16-bit which can assume a val-
ue from -32768 to +32767 in two’s complement. The holding Register (REG)
Denitions, Units of measurement, and Scaling factors are shown below.
Access is ‘r’ (read) or ‘w’ (write).
REG DEFINITION UNIT SCALING ACCESS
0 Current moisture concentration (Moisture= 51 Hex) PPM 100 r
1 Concentration held during verication (HeldConc= 52
Hex)
units 100 r
2 Sensor frequency (Frequency= 53 Hex) Hz 1 r
3 Delta frequency (DeltaFrequency= 54 Hex) Hz 100 r
4 Flow reading (Flow= 55 Hex) SCCM 100 r
5 Sensor pressure (Pressure1= 4B Hex) kPa 100 r
6 Electronics temperature (EETemp= 4C Hex) C 100 r
7 Sensor temperature (CellTemp= 4d Hex) °C 100 r
8 System alarms and warnings (SystemState= 5F Hex) — 1 r
9 Flow control output (Loop1Duty= 60 Hex) — 100 r
10 Heater control output (Loop2Duty= 61 Hex) — 100 r
11 Reading is ready (DataState= 62 Hex) — 1 r
12 Sensor pressure analog input (Analog0= 64 Hex) counts 1 r
13 Flow analog input (Analog1= 65 Hex) counts 1 r
14 Sensor temperature analog input (Analog2= 66 Hex) counts 1 r
15 Process pressure analog input (Analog3= 67 Hex) counts 1 r
16 Analyzer cycle status (OutputState= 68 Hex) — 1 r
17 Reference period counter (ReferencePer= 69 Hex) second 1 r
18 Sample period counter (SamplePer= 6A Hex) second 1 r
19 Wet sensor frequency reading (WetFreq= 6B Hex) Hz 1 r
20 Dry sensor frequency reading (DryFreq= 6C Hex) Hz 1 r
21 Verication cycles counter (CalcCycleCount= 6F Hex) minute 1 r
22 Electronics temperature input (AnalogEE= 70 Hex) counts 1 r
23 Current ow reading (CurrentFlow= 8A Hex) SCCM 100 r
24 Maximum ow deviation (MaxFlowDev= 8E Hex SCCM 100 r
25 Special command (ModbusCommand= 93 Hex) — 1 r,w
26 Sensor pressure coecient (Pressure1Span= 2 Hex) kPa 100 r,w
27 Sensor pressure oset (Pressure1Oset= 3 Hex) kPa 100 r,w
Serial Communication Interface | 6-5