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Time Management

The Grundfos ALPHA HWR pump maintains an internal real-time clock (RTC) used for schedule execution (e.g., Comfort Level scheduling) and event logging. This guide explains how to read, synchronize, and understand the pump's timekeeping mechanism.

Overview

The pump's timekeeping is managed via GENI DataObjects (Class 10). While older protocols used simple Unix timestamps (Class 14/16), modern firmware relies on Object 94, which provides a structured date and time representation (Year, Month, Day, Hour, Minute, Second, etc.).

Key Objects

Object SubID Name Description
Object 94 101 DateTimeActual The actual local Date and Time.
Object 94 100 DateTimeConfig Configuration for setting the local Date and Time.
Object 94 102 DaylightSavingTime DST configuration.
Object 94 103 UtcOffset UTC offset (default is CET/UTC+1).

Using the CLI

The simplest way to manage the pump's clock is via the alpha-hwr clock command group.

View Clock

To check the current pump time vs. your system time:

alpha-hwr clock view

Example output:

Connecting to configured device...
Pump Clock:   2026-01-30 11:35:42
System Clock: 2026-01-30 11:55:12
Offset:       +1170.0 seconds

Sync Clock

If the pump clock has drifted or was never set (often showing dates in 1970-1974), you can synchronize it with your current system time:

alpha-hwr clock sync

This command performs several steps:

  1. Constructs a DateTimeConfig payload matching your system time.
  2. Sends the command using MTU fragmentation (required for the 21-byte packet).
  3. Sends a mandatory Configuration Commit to persist the changes.

Using the Python API

You can programmatically manage the clock using the AlphaHWRClient and its clock service.

Read via API

from alpha_hwr import AlphaHWRClient

async with AlphaHWRClient(address) as client:
    await client.authenticate(fast_mode=True)

    clock = await client.clock.get_clock()
    if clock:
        print(f"Pump time: {clock}")
    else:
        print("Clock is unset or failed to read.")

get_clock() returns a standard Python datetime object. If the pump returns an uninitialized state, it may return epoch time (1970-01-01).

Sync via API

await client.clock.set_clock()  # Synchronizes with current LOCAL system time
# OR
from datetime import datetime
await client.clock.set_clock(datetime(2026, 12, 25, 10, 0, 0))

Protocol Details

MTU Fragmentation

The ALPHA HWR has a strict 20-byte MTU limit for BLE writes. Setting the clock requires a 21-byte GENI packet. The library automatically splits this into two writes (20 bytes + 1 byte) with a small delay.

Configuration Commit

After writing to DateTimeConfig (SubID 100), the motor controller requires a Commit command to apply the changes. The library automatically handles this to finalize the synchronization.