Operating Instructions

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Siemens TX-I/O™ Module system – Functions and operation CM110561en_08
Building Technologies Indicators and operator controls 2018-10-25
2.3.2 Override status LED
The yellow "Override" LED indicates that local override is active:
Description
LED (yellow)
Normal (Automatic operation)
OFF
Local override active
ON
Multi-stage function
• The function can be overridden on any I/O point associated to the
function
• LEDs of all the associated I/O points flash when operated
Reminders / Errors For details about errors please refer to the section "Indication,
operation, and diagnostics" in the TX-I/O™ Engineering and
installation guide [6].
2.3.3 Priority
Local override has first priority, followed by the various "functional tests" and (lastly)
operation via process value.
2.4 Address key
• Without an address key, the module is in a secure, inactive state
• With the address key inserted, the module has its full functionality
• The module address is mechanically encoded in the address key
• Based on to the address the module receives information via the bus indicating
which field devices are connected to this address, and which function is required for
the field devices.
• When replacing the plug-in I/O module, the address key must FIRST be swiveled
outward. This causes the load to be switched off and the values to be saved in the
bus master. The key remains plugged into the terminal base and can indicate the
required function to the new plug-in I/O module.
2.5 Function of the modules within the
I/O subsystem
0.5 seconds after switching on the module supply DC 24 V via bus the modules are
ready for communication.
Overall functionality of the I/O modules is based on the interaction of the following
elements:
– Module (hardware)
– Firmware (functions)
– Configuration and parameter-setting of the I/O functions (see [8], [9])
– Communication via the bus
– Measurement and control application in the room automation station / the automation
station
Start-up response of
the modules
I/O subsystem