Pepperl+Fuchs KFD Series, Manual

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HART Multiplexer System KFD*-HM*-16
Commissioning
201
8-04
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5.2.4 Switch-On Behavior
When the power supply has been switched on, the multiplexer master performs an
initialization process with a self-test. The process is indicated by a flashing green LED.
Any faults detected are indicated by a red LED. The multiplexer devices defined in
the multiplexer table (command 157) are then scanned for any available HART-compatible
field devices. This process is indicated by the flashing orange LED.
Once the multiplexer master has completed the scan process, a list of the field devices
connected is saved in the device.
The factory setting for the number of message repeats is set to 2. The search duration is
between approximately 30 seconds and several minutes in the case of maximum
configuration. On completion of this phase, the orange LED goes out. Volatile data is set to its
default setting. Data stored in non-volatile memory is retained.
Note!
If a field device is connected to the multiplexer device during operation, a scan must be
performed afterwards so that the field device can be addressed via HART. This scanning
process is triggered automatically when the multiplexer device is switched on,
see chapter 7.1.5. The process can also be started manually in the maintenance station,
see chapter 7.2.1. The duration of the scanning process is dependent
•
on the number of connected multiplexer slaves,
• on the number of connected HART-compatible field devices,
• on the loop search type, see chapter 9.1, command 153,
• on the number of message repeats in the case of a fault, or
• on whether the query has been answered.
Note!
Scanning Process with Several Interconnected Multiplexer Devices
If several multiplexer devices are interconnected through a shared RS-485 line and
a field device is replaced between the multiplexer devices, a scan must be performed
on both multiplexer devices. Otherwise, no communication with the affected field device is
possible.