Technical data

DW 11
Bit no.
Name Meaning
Table 6-11 continued:
11.8 BUMP = 1: No bumpless changeover from manual to automatic
= 0: Bumpless changeover from manual to automatic
11.9 to 11.15 Irrelevant
6.32.3
OB 250: Initializing the
PID Algorithm
Function OB 250 initializes the PID algorithm and is called in the restart
OBs 20/21/22.
Parameters The parameters required for the initialization are contained in the
transfer data block (DB x).
Note
The transfer data block must be open before OB 250 is called.
For data transfer, each controller requires its own DB x (x
≤254).
From this, the system program automatically generates a further
DB x + 1 in the data block RAM, that the controller uses as a data
field in cyclic operation. This means that the corresponding DB
numbers must still be available. Data blocks DB x + 1 represent the
data interfaces between the controller and the user or peripheral I/Os.
Possible errors Internally, OB 250 uses OB 254 or OB 255 (duplication of data
blocks). In the event of an error, the CPU recognizes a runtime error
and calls OB 31. If this is not programmed, the CPU goes to the stop
mode. The error IDs entered in ACCU 1 then refer to OB 250.
OB 250/251: Closed-Loop Control/ PID Algorithm
CPU 928B Programming Guide
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