ABB AZL402 simulator template: register layout
The register layout the Modbus Poll slave simulator uses for a ABB AZL402: Water Quality Analyzer (pH, ORP, Turbidity, DO, Cond, Temp). This is a test layout built into the app, not the manufacturer's own register map.
This is a test layout, not the manufacturer's register map. It is the layout the slave simulator in Modbus Poll uses so you can practise and test a SCADA or script without the real device. A real ABB AZL402 uses different addresses.
- Protocol
- Modbus TCP (simulator)
- Addresses in the manual
- 0-based protocol addresses, as sent on the wire
- 32 and 64-bit values
- High word first (AB CD)
- Registers listed
- 7
- Source
- voltrus-explorers apps/modbus-poll/src/templates.ts at commit 1933046
Address base. Addresses are the 0-based wire addresses Modbus Poll uses. The simulator packs the values one after another from the base address. Address 200 in the manual is address 200 on the wire.
Word order. The simulator writes 32-bit floats with the high word first and 64-bit counters as big-endian doubles over four registers.
Modbus Poll and the Modbus protocol itself count from 0. The "Wire address" column is the number to type into Modbus Poll.
Downloads
The register table has every column on this page. The blocks file imports into Modbus Poll. The template JSON holds the same blocks plus unit, scale and access for scripts.
Registers
| Manual | Wire | Register | Type | Regs | Unit | Scale | Access | Area |
|---|---|---|---|---|---|---|---|---|
| 200 | 200 | pH valuepH · Simulated value, starts near 7.2. |
float32 | 2 | pH | 1 | RW | Holding (FC03) |
| 202 | 202 | Oxidation-reduction potentialORP · Simulated value, starts near 245. |
float32 | 2 | mV | 1 | RW | Holding (FC03) |
| 204 | 204 | Water turbidityTurbidity · Simulated value, starts near 0.45. |
float32 | 2 | NTU | 1 | RW | Holding (FC03) |
| 206 | 206 | Dissolved oxygen concentrationDissolved_Oxygen · Simulated value, starts near 8.2. |
float32 | 2 | mg/L | 1 | RW | Holding (FC03) |
| 208 | 208 | Electrical conductivityConductivity · Simulated value, starts near 485. |
float32 | 2 | µS/cm | 1 | RW | Holding (FC03) |
| 210 | 210 | Free chlorine residualChlorine_Free · Simulated value, starts near 0.85. |
float32 | 2 | mg/L | 1 | RW | Holding (FC03) |
| 212 | 212 | Water temperatureTemperature · Simulated value, starts near 15.8. |
float32 | 2 | °C | 1 | RW | Holding (FC03) |
Scale is the number to multiply the raw value by to get the unit. Types with more than one register (32 and 64-bit) follow the word order above.
Open in Modbus Poll
- Download the Modbus Poll blocks file.
- Open Modbus Poll, connect to the device and set its unit ID. In Modbus Poll set Word order to AB CD.
- In the blocks panel on the right, click Import CSV and pick the file. CSV import is a Pro feature. Without Pro, Modbus Poll polls the first 20 values of your blocks.
- The wire addresses are already in the file, so there is no 0-based or 1-based conversion to do.
Once the values look right, export the tag list to Ignition, Kepware, Node-RED, Home Assistant or Voltrus SCADA.
Source and accuracy
Source: Modbus Poll source code, device templates (github.com)
voltrus-explorers apps/modbus-poll/src/templates.ts at commit 1933046. Read on 2026-10-24.
This layout is part of the open source Modbus Poll app.
Found a mistake? Report it by email with the register address and the manual page.