NORD Drivesystems BU0550 - Manual (Page 76)

PLC logic for NORD SK 54xE frequency inverters
76 BU 0550 GB-0813
NOTE
Attention ! The memory range in the setting MEMORY = 0 is also used by the Scope
function. Use of the Scope function overwrites the saved values!
3.5.9.3 FB_ReadTrace
The memory areas of the FI can be read out directly with the aid of this FB.
If the FB detects a positive flank on ENABLE, all parameters with are present on the input are adopted. The
memory address which is to be read out is labelled via STARTINDEX and MEMORY. If the reading process
is successful the output VALID changes to 1 and the value which is read out is in VALUE.
If the FB is now called up several times and the ENABLE input remains at 1, with each call up the memory
address which is to be read out is increased by 1 and the content of the new memory address is immediate-
ly copied to the output VALUE.
The current memory index for the next access can be read out under the output ACTINDEX. If the end of
the memory is reached, the output READY changes to 1 and the reading process is stopped.
Values can be read in INT or DINT format. For INT values only the Low part of the VALUE output is to be
evaluated. The assignment is made via the SIZEinput; a 0 stands for INT and a 1 for DINT values.
The assignment of the memory areas is made via the MEMORY input:
MEMORY = 1  P613[0-251]
corresponds to 504 INT or 252 DINT values
MEMORY = 0  P900[0-247] to P906[0-111] corresponds to 3200 INT or 1600 DINT values
The FB cannot be interrupted by other blocks
With a negative flank on ENABLE all outputs are set to 0 and teh function of the FB is ended.
Table 102 FB_ReadTrace
VAR_INPUT VAR_OUTPUT
Input Explanation Type Output Explanation Type
ENABLE Execute BOOL VALID Reading process successful BOOL
SIZE Memory format BOOL READY The entire memory has been read
out BOOL
MEMORY Selection of memory area BYTE ERROR the FB has an error BOOL
STARTINDEX Indicates the memory cell to
be written to INT ERRORID Error code INT
ACTINDEX Actual memory index, to which will
be read in the next cycle INT
VALUE Value read out DINT
ERRORID Explanation
0 No error
1A00h STARTINDEX value range exceeded
1A01h MEMORY value range exceeded