Device automation logic #8

New Issue

jarno · 2023-01-18T23:55:21+02:00

jarno commented

2023-01-18 23:55:21 +02:00

Since the whole project started about interfering with the slightly unreactive control logic of the device, the logic to do should be implemented. However, some important features are not accessible over the modbus interface:

Circulation Fan control
Water radiator valve control
Min/Max supply air temperatures

Those 3 would be the main methods of controlling the heat output, but none can be controlled via modbus. There is however the possibility of disabling active heating altogether. With the current configuration (which is the only one that keeps the house warm) the heater valve is basically fully open all the time.

It is known from the datasheet of the electric servo controlling the 3-way valve that it takes 60 seconds to go from fully open to fully closed and vice versa.

After the heating is re-enabled, it looks like it takes quite some time to restore the valve back to the fully open position. During this time the device doesn't seem to even try to go full open, instead it increases the heat little by little, hoping to reach the set minimum temperature with the valve as closed as possible.

There may be the possibility of disabling active heating for a short period, possibly for just a few seconds, to force the device to lower the water temperature, after which it starts creeping up slowly. Putting the device on max heating mode should logically make the device try to go to full heating as quickly as possible, but this doesn't seem to be the case. Max heating may still be useful for the controlling. Needs quite a bit of trial and error.

The different away states could maybe used to allow controlling the circulation fan speed.

Since the whole project started about interfering with the slightly unreactive control logic of the device, the logic to do should be implemented. However, some important features are not accessible over the modbus interface: - Circulation Fan control - Water radiator valve control - Min/Max supply air temperatures Those 3 would be the main methods of controlling the heat output, but none can be controlled via modbus. There is however the possibility of disabling active heating altogether. With the current configuration (which is the only one that keeps the house warm) the heater valve is basically fully open all the time. It is known from the datasheet of the electric servo controlling the 3-way valve that it takes 60 seconds to go from fully open to fully closed and vice versa. After the heating is re-enabled, it looks like it takes quite some time to restore the valve back to the fully open position. During this time the device doesn't seem to even try to go full open, instead it increases the heat little by little, hoping to reach the set minimum temperature with the valve as closed as possible. There may be the possibility of disabling active heating for a short period, possibly for just a few seconds, to force the device to lower the water temperature, after which it starts creeping up slowly. Putting the device on max heating mode should logically make the device try to go to full heating as quickly as possible, but this doesn't seem to be the case. Max heating may still be useful for the controlling. Needs quite a bit of trial and error. The different away states could maybe used to allow controlling the circulation fan speed.

jarno commented

2023-02-18 17:36:37 +02:00

Another method might be to switch between the dynamic fan circulation speed (set to lower RPM) and manual speed setting (set to a higher RPM). If room temperature gets too high, switch to the dynamic mode, and after temperature has lowered a bit, switch back to the manual setting.

In this scenario the dynamic mode would be configured to 20% circulation, both min and max. The manual setting would be higher, the normal setting.

The fan speed settings need to be done from the device control panel, it doesn't seem they can be altered over Modbus.

Another method might be to switch between the dynamic fan circulation speed (set to lower RPM) and manual speed setting (set to a higher RPM). If room temperature gets too high, switch to the dynamic mode, and after temperature has lowered a bit, switch back to the manual setting. In this scenario the dynamic mode would be configured to 20% circulation, both min and max. The manual setting would be higher, the normal setting. The fan speed settings need to be done from the device control panel, it doesn't seem they can be altered over Modbus.

jarno commented

2023-02-18 18:15:00 +02:00

deleted

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