Saia-Burgess Controls AG
Manual for PCD2.W745 and PCD3.W745
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Document 26-796 E
NG06 │ 2018-10-12
Programming
Programming with series xx7
3
3-7
3.2
Programming with series xx7
The access from Step
®
7 via the local I/O bus (LIO) to the thermomodule PCDx.W745
is done with direct peripheral commands. The module is using 4 input bytes and 4
input words (together 12 bytes). All possible accesses through this peripheral window
are described here. The configuration of the module is done with the peripheral defini
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tion (Hardware-DB). It is not possible to change configuration in run.
The PCD3.W745 can be used as well in a local extension (LIO) as in a Profibus-DP
extension (RIO). The PCD2.W745 can only be used via the local I/O-bus
Using the modules with Profibus-DP RIO the 4 temperature values are sent to the
master as words. The status registers are transferred as 4 bytes. The configuration of
the PCD3.W745 is done in the DP configuration. It is not possible to change configu
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ration in run.
Due to technical reasons it is not possible to have acces to the module within the
start up OB 100. All access during this phase is forbidden. This restriction is valid for
the CPUs PCD1 and PCD2.M1x7. The PCD2.M487 allows to have access during the
start up.
Peripheral Bios: Identification and error detection
The data block with the peripheral definition of the PCDx.W745 can be easily created
by using the I/O-Builder (Version 2.002 or higher). This software tool can be down
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loaded free of charge from the web page:
www.sbc-support.com
The identification (Kennung) of the PCDx.W745 is 22 (h). Additionally to that only a
range of 12 input bytes has to be defined in the peripheral definition of the local I/O
bus (DB 1, DB 511 or DB 1023). When this range is within the process image the
data are refreshed automatically every cycle.
Additional initialization values like sensor type, measurement type and measurement
unit are set in the peripheral definition. A detailed description about that follows in
chapter ‘peripheral definition’.
The initialization values in the peripheral definition are sent to the module when
changing from stop mode to start up mode and the module will be initializised.
If an error occurs during the initialization the diagnostic interrupt OB 82 is called up.
The reason for the error can be read from the local data.
