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Program Transfer
Procedures
SIMATIC TIWAY I Series 500 NIM User Manual
Exception when Reading. The device performing the Primitive operation
aborts execution of a Primitive when an exception condition is encountered,
and returns the reason for the exception. The device requesting the
Primitive should evaluate returned message, take appropriate corrective
measures, and attempt retransmission of the Primitive.
Exceptions when Writing. Exceptions concerning Primitive format,
contents, or device state when writing will abort the entire Primitive. Some
exceptions indicate an error during execution of the Primitive. In this case,
the data elements specified in the Primitive may or may not have been
modified. Therefore, when the exception condition is returned to the sender,
all data element locations specified by the failed Primitive should be
re-written. The station sending the Primitive should examine the exception
reason, take appropriate corrective measures, and try to send the Primitive
again.
The data needed to archive or restore the operating environment of a device
will vary from one device to the next. Relevant data may be Relay Ladder
Logic (RLL) programs and associated configuration parameters, controller
process control loop information, or a machine configuration list from a
UNILINK Secondary Adapter. To release the network host from having to
record the various and diverse data types associated with this information,
the program upload/download concept was developed. The program
upload/download Primitives allow the network host to archive or restore
operating environments from different types of network secondaries in a
standard (or generic) fashion.
To keep the transfer as device independent as possible, several unique
procedures have been defined to allow easier resource management:
Initialize Upload/Initialize Download — places the attached device
(controller, robot, CNC machine, etc.) in a safe, non-operational state,
and defines the types of data to be uploaded or downloaded.
Transfer Upload/Download data — transfers all operating environment
data. These transport utilities are managed in a sequential manner to
ensure proper sequencing of data frames.
Terminate Upload/Download — terminates all program
upload/download activity and returns the attached device to its original
operating condition (if possible).
Four Primitives have been developed to complete the above tasks. Primitive
07 allows you to query the attached device for the type of program segments
it contains. Primitives 58 and 59 provide data upload and download
capability. Primitive 06 allows you to terminate the program transfer and
return the attached device to its previous state.
NIM Primitives
4-7
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