Samson 5476 manual Activating the meter bus, Communication

Communication

Note!

A 15 V DC supply voltage (+15 V at terminal 15 connected to the meter bus connection terminal

3)can be used at the WMZ connection of TROVIS 5476 Controller when the red jumper on the back of the controller is located pointing towards the edge of the controller (Fig. 8). Otherwise, the meter bus module in the heat meter is supplied. Furthermore, the heat meter is galvanically connected with controller input side (pulse and current input at terminal 15) resulting it being connected to the Modbus interface as well which can lead to the communication coming to a standstill.

9.4.1 Activating the meter bus

To successfully transfer data from the heat meter to the controller, the heat meter must use a standardized protocol in accordance with EN 1434-3. It is not possible to make a general state- ment about which specific data can be accessed in each meter. For details on the different meter makes, refer to the technical documentation TV-SK 6311. All necessary function block parame- ters to set up the communication with heat or water meters are available in function block FB 29. The meter bus address, the model code and the reading mode must be specified for the heat meters WMZ1 to WMZ3.

A meter bus address must be unique and correspond with the address preset in the WMZ. If the preset meter bus address is unknown, a single heat meter connected to the controller can be as- signed the meter bus address 254. The address 255 deactivates the communication with the re- spective WMZ. The model code to be set for the heat meter can be found in TV-SK 6311. In gen- eral, the default setting of 1434 can be used for most devices. The meters can be read either au- tomatically every 24 hours (approx.), continuously or when the coils (= Modbus data points) as- signed to the heat meters WMZ1 to WMZ3 are overwritten with the value 1 via the system bus interface.

Function	WE	Configuration
Meter bus	OFF	FB29 = ON
	254*	Meter bus address for WMZ 1 to 3 (ST.-NO) / 0 to 255
	1434	Model code WMZ 1 to 3 / 1434, CAL3, APAtO, SLS
	Cont	Reading mode WMZ 1 to 3 / 24h, Cont, CoiL

* WE for WMZ 2 and 3: 255

9.4.2 Flow rate and/or capacity limitation via meter bus

Similar to the flow rate limitation based on a standardized 0/4 to 20 mA signal, the update rate of the measured variable, flow rate and/or capacity, must be smaller than 5 seconds in meter bus operation to carry out a proper limitation. Refer to the technical documentation TV-SK 6311

EB 5476 EN 71