6
Installation
and Operation
EDBC250SIO | 2.0
164
6.2.2
Order of Safety I/O-modules in c250-S Systems
Power to the logic circuitry of the safe I/O modules is drawn from the 5 V of the backplane bus.
Withdrawing the required current will also provoke a drop in the backplane bus voltage. The
more modules there are on the backplane bus, the further the voltage may drop. The safe I/O
modules monitor the 5 V supply to the logical circuit and change to the safe state when there
is not enough voltage for sustained operation. Remember the fact when installing the system.
Note, information
Order of modules in c250-S systems
In order to ensure that the entire c250-S system works properly, arrange the
c250-S modules by their specific E-bus load, placing the modules with the high-
est E-bus load immediately next to the head module (bus coupler or controller).
Take account of the head module's maximum bus load.
If possible, place the Safety I/O-module immediately next to the head module.
Note, information
Stick to the order of modules set in PLCDesigner because it will otherwise be im-
possible to get the system operational.
6.2.3
Snapping on a Single Module
•
Push up the module against the mounting rail from below, allowing the metal spring to
snap in between mounting rail and mounting area as illustrated.
•
Push the top of the module against the mounting wall until it snaps in.
I
I
Figure 3: Rail mounting of module
