Manual – Fieldbus Interface INTERBUS UFI11A
39
5
INTERBUS Interface
Variable data
channel performs a
read type service
A PCP WRITE service has to be performed before a parameter can be read via the data
channel. The PCP WRITE service defines where the UFI11A data should be available.
A read service must take place on the variable data channel in order for these data to
get to the master. As a result, a PCP WRITE and a PCP READ are always required for
performing read services via the variable data channel. The following table shows how
read services are performed via the variable data channel.
1. Reception is confirmed immediately, the data channel is evaluated and the reques-
ted service performed.
2. Service confirmation is entered in the data channel and can be evaluated by READ
access in the master.
The "variable data channel with acyclical routing" object is only handled locally on the
fieldbus interface and is defined as in the following table.
Control (master) UFI11A fieldbus interface
1. Initiate the service coded in the parameter channel by means of a WRITE to the "MOVILINK parameter
channel cyclical" object.
WRITE 8288 (parameter channel)
OK
2. READ "MOVILINK parameter channel cyclical" and evaluation of the service confirmation in the para-
meter channel.
READ 8288 (parameter channel)
Data = Parameter channel with result
Index: 8288
Object code: 11 (string variable)
Data type index : 10 (octet string)
Length: 11
Local address:
Password:
Access groups:
Access rights: Read all/Write all
Name[16]: -
Extension length: -
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