CMX 40 - Expanding an L-bus
- Run hardware EPI, unlink and relink all units on the affected L-bus.
All units must alays be ready for operation (fuse inserted).
The problem can be avoided by at least two operable units always being present on the L-bus during linking.
If necessary, the single linked unit must first be unlinked after plugging in the new unit.
Problems occure when expanding a L-bus consists of only one unit.
From system package 3.01 on the subscriber number 1, and thus also the pass-through function, is assigned twice.
Only a single CMX module (without redundance) is linked on this L-bus. Other CMX modules are to be linked on this L-bus, whereby the existing CMX module acts as the linking unit.
- The individual unit sends no telegrams on the bus, as no other subscribers are entered.
As a result, this subscriber is not entered in the newly inserted units, so that at first the subscriber list remains empty in the new units. When linking the first new unit, it receives the first linking command from the A-bus and also links itself on the L-bus (as subscriber 1 with pass-through function) due to the empty L-bus subscriber list.
Result: Collapse of the bus traffic on the L-bus.