BLOCK TRANSFERS
In order to read or write data via block transfers, the PLC has to be programmed
accordingly. Refer to the Allen-Bradley PLC documentation on how to write block
transfer read (BTR) and block transfer write (BTW) rungs in your PLC program.
This section describes the meaning of the data read and written in block transfers to the
Milltronics device.
The data provided by the Milltronics device in a BTR operation to the PLC is set by a
BTW operation.
Block Transfer Write
The words in the block transfer write operation allow access to the Milltronics devices in
two ways: Multiple Parameter Access (MPA) and Single Parameter Access (SPA).
word
description
0
point on priority
1
parameter number, MPA
2
parameter index, MPA
3
decimal place, MPA
4
format, MPA
5
parameter number, SPA
6
point number, SPA
7
parameter index, SPA
8
value, SPA
9
decimal place, SPA
10
format, SPA
11
read/write flag, SPA
12
operating mode, SPA
Words 1 to 4 are MPA, allowing continuous monitoring in BTR words 21 – 30 of
selected parameters for points 1 – 10. Using these words does not allow changing of
the parameter value.
Words 5 to 12 are SPA, allowing continuous monitoring or demand programming of a
parameter for a given point, individually selected for each point.
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Milltronics SmartLink 3/31/97 1:16 PM Page 11
