Weishaupt WPM (SG Ready)

Installation

1. 1Enable Modbus TCP on the WPM by navigating to the communication or Modbus section in the expert menu, setting access to 'On', and entering the IP address or subnet of the ModbusCloud Gateway as the permitted client.
2. 2Connect the WPM to the same LAN segment as the ModbusCloud Gateway using a standard Ethernet cable and confirm the WPM responds on port 502 using a port scan or ping before proceeding.
3. 3In the ModbusCloud portal, add your Gateway, import the Weishaupt WPM (SG Ready) template, and assign Modbus unit ID 1 (the WPM default) along with the WPM's IP address and port 502.
4. 4Verify the connection by spot-checking register 32102 in the portal and confirming the displayed domestic hot water temperature matches the value shown on the WPM display, applying a scale factor of 0.1 to the raw value.

Things to watch for

01

The gateway connects but all registers return errors. What is wrong?

The WPM whitelist only allows the specific client IP or subnet entered in its Modbus TCP settings. Confirm that the ModbusCloud Gateway's IP address matches the network address configured in the WPM expert menu under the Modbus TCP section. A mismatch causes the WPM to refuse all connections silently.

02

Register 32102 shows a value that looks too large. How do I interpret it?

The WPM returns raw int16 values scaled by a factor of 0.1. A raw reading of 523, for example, represents 52.3 degrees Celsius. Apply scale 0.1 in the portal channel configuration. Without this scaling the displayed value will be ten times the actual temperature.

03

Why do registers 35101 and 35102 not change after I write to 45101 or 45102?

Registers 35101 and 35102 reflect the configured SG Ready behaviour for each contact, not necessarily the live commanded state. Allow a polling cycle to complete after writing. Also note that the WPM may have minimum reaction times of several minutes before the operating mode visibly changes.

04

Is it safe to write any value to the SG Ready setpoint registers?

Use write registers 45101 and 45102 with caution. Writing an unintended mode can force the heat pump into a boosted or blocked state that overrides normal heating schedules, potentially causing thermal discomfort or increasing grid consumption unexpectedly. Always test writes during low-demand periods and revert to the neutral mode (0) after testing.

Registers (5)

3 read / 2 write

More TCP templates

Domekt R 400 V

Komfovent

Modbus TCP

Controls Komfovent Domekt recuperator ventilation via Modbus TCP

25 registers118

Fronius - Modbus TCP

Fronius

Modbus TCP

Monitors Fronius Symo and Primo inverters via Modbus TCP

15 registers597

NIBE Nibe S-Series (SG Ready)

NIBE

Modbus TCP

5 registers1

SunSpec Model 709 — DER Trip LF

SunSpec

Modbus TCP

9 registers

Victron Meter AcOut

Victron

Modbus TCP

16 registers

FoxESS Avocado (grid)

FoxESS

Modbus TCP

8 registers