Alicat PROFIBUS - Manual (Page 4)

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4.1 Wait Parameterization
After baud rate detection, or if PROFIBUS communications have been
stopped and restarted, the unit will be in wait parameterization state. Items
that are parameterized are gas select and error mode for the totalizer (if
totalizer equipped).
4.1.1 Gas Select
The default gas select in the GSD file is “keep current.” This particular gas
select tells the unit not to change the gas select that the unit had the last time
it was powered up. Therefore, if the user wants to keep the factory default gas
of the unit as it was ordered, leaving this at “keep current” will achieve that.
All Alicat standard gases are available in the parameterization section. If the
user wishes to change the gas select “on the fly”, this can be done via the
command word and is described in the data exchange section.
4.1.2 Totalizer Rollover
If a unit is equipped with a totalizer, the way the unit will respond to a rollover
event can be modified with this parameter. The error mode parameter for the
totalizer allows the user to set one of three modes for the totalizer.
These modes are: No Rollover with Error, Rollover with Error, and Rollover
with No Error.
It is important that this parameter is set if a mode other than the default
set by the GSD is desired.
This is required because every Alicat unit that is configured on the network will
take on the default setting in the GSD file. PROFIBUS equipped units that are
not equipped with totalizer function will ignore this parameter.
4.2 Wait Configuration
To allow user flexibility, all PROFIBUS equipped Alicat units are modular on a
PROFIBUS network. The user can pick and choose which input(s)/output(s)
to/from the master are desired. These modules can be configured in any
order and number as long as the total number of bytes does not exceed the
maximum set in the GSD file.
While waiting for configuration, the meter/controller will accept and verify the
configuration telegram. If an incorrect configuration is attempted, it will be
immediately rejected.
Note that at this time all configurations that are valid in structure are accepted
as being valid. Any input value to the master that is not supported by the unit
will always input a zero. All outputs from the master that are not supported by
a particular meter/controller configuration will be ignored.
After power cycle a unit will default to the following configuration:
Reading:
0x42,0xA4,0xA4,0x01
Set-point: 0x82,0x03,0x3,0x0B
Control Register: 0x82,0x00,0x00,0x0C