Railline, several Modbus addresses for the same variable? PMA Railline interface manual
- PMA Railline interface manual:
- Variables can be accessed in several ways over the different interfaces.
- These interface descriptions list a selection of possible data of 1 device.
- According to the hard- and software options there are different variables available.
- Additionally, the data bases they are made of contain “all possible” data of at least the controller family, e.g. Rail line.
- The single device does not need them all. This explains the gaps in the Modbus addresses.
- You can access variables by their direct Modbus address e.g. via Modbus RTU.
- Some data are copied to a special area to have them more compact:
- Signals needed by BlueControl are automatically copied to an area called “Visual”.
- This is what customers asked for to see in BlueControl’s Online mode, or what you can save as a BlueControl trend.
- This data has been made available for customers.
- And a customer can create his own list of data:
- Add variables of a RL module into bus cache via “bus data read” and “… write”, e.g for the KS45 in Rail line.
- Then the bus coupler collects and updates the data from all the modules in the RL system in the background.
- If a message asks a value, the bus coupler can answer from his cache.
- After creating this list while commissioning, this communication is just what you need, quick and compact.
- Another advantage: You can ask several values from the cache in 1 message.
- Therefore there are different Modbus addresses for the same variable.
- Of course, under certain conditions some variables look the same, as long as the conditions match:
- Like SP(intern) and SP(eff.ective) show the same value, if the setpoint is switched to SP, not to SP2,
- no ramp working, no profile running etc.
