Atlas Copco PowerMACS 4000, Руководство пользователя

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5.3.3 ID device variables
The following input and outputs can be used to control and monitor the Stations Work piece identifier
function. See chapter: Advanced Station Settings for this is set up.
Inputs:
Variable Type Use
IDSTATUS INT Status for ID device read or write operation:

0: Idle and OK

1: Idle and NOK

2: Busy
Note that the read ID string is not valid until this signal is 0. After
issuing an IDREAD you should always wait one PLC scan before
evaluating IDSTATUS.
CURRIDSTRING STRING(40) This input always reflects the ID string known by the station. Will be
included in the cycle data as the station level variable "Wp ID".
IDCODE INT Code from conversion of read ID string. See chapters: Conversion
table for how the conversion is defined.
Outputs:
Variable Type Use
IDREAD BOOL Set to True to order reading of ID device connected to the station.
IDWRITE BOOL Set to True to replace the ID string currently known by the station with
the value of IDSTRING.
If the station is connected to an ID device this device will be used to
generate a corresponding IDCODE. The written value will be echoed
back to CURRIDSTRING.
IDSTRING STRING(40) String to replace the ID string currently known by the station.
Sampled on the positive edge of IDWRITE.
The station will only use an ID string once. When it starts a cycle it will clear its internal ID string, and
therefore also CURRIDSTRING, and then set the value of IDCODE to
–32768.
Depending on which type of ID device that is used a read operation may take differently long time. For a
barcode reader the last string scanned by the operator is stored internally by PowerMACS system so
completing a read is done within less a few milliseconds. However, for devices of Escort memory, where
the external data tag is read using a communication protocol, a read operation may take much longer
time. You should therefore always check the input IDSTATUS to make sure that a read string is available
to the station before you issue a start order.