OAS Open AutomationSystems GmbH
Page
1
of
6
OAS-SBS-IOMR-1026
Digital outputs 16A: 4 digital outputs 16A: 4 DO relay outputs each with LED and push button
operation
The digital output module
OAS-SBS-IOMR-1026
is a Local Override/Indication Device (LO/ID)
which is used to control four lighting circuits, or
other digital actuators. By means of the integrated
push buttons, it provides the ability of manual
override of the DOs which are usually controlled
via MODBus commands.
The relay outputs provide the normally open
contact of each relay and will be contacted via
terminals. They are implemented using
bistable
relays
.
For each DO there are two LEDs present for
indicating the status. The left LED signalizes
whether the output is controlled via Modbus commands or whether it is manually overridden by the push
button, whereas the right LED indicates the output's state (ON or OFF).
The possibility of manually overriding the digital outputs by means of the push buttons can be disabled
by using the settings in a register ('Setting the mask for manual override of the Dos’). This can be defined
for each DO separately. Changing between the modes ‘Automatic’ and ‘Manual’ is done by holding down
the push button. The time required for this can be set together for all four channels. If a button is pressed
for a too short time, the left LED ('Automatic') flashes orange for one single time shortly after releasing
the button. If, however, the channel is blocked for manual override due to the settings in the mask, this
LED flashes permanently during the button is pressed.
There is a register available that shows whether and which push button has been pressed since the last
time this register has been read. When reading this register, all bits will be reset to zero. The current
state of the push buttons and the outputs as well can also be read out via registers.
Furthermore, via a register there can be configured whether the outputs shall start in automatic mode
or manually overridden (OFF). In addition, a delay time can be defined, which must elapse between the
switching of two outputs at least. Thus, the system perturbations resulting from the switching operations
can be reduced.
All digital outputs can be configured so that they will assume a defined state (‘safe state’) if the module
has not received valid bus telegrams via the MODBus for a certain time. These predefined states are
set separately for each output, whereas the time until activating the safe state is common for all outputs
of a module.
