NORD Drivesystems BU0550 - Manual (Page 75)

3 AWL (Instruction List, IL)
BU 0550 GB-0813 75
3.5.9 Access to memory areas of the frequency inverter
If it is necessary to temporarily save large amounts of data, to hand this data over to other devices or to re-
ceive it from other devices, it is then advisable to use the modules FB_WriteTrace and FB_ReadTrace.
3.5.9.1 Overview of storage modules
Function module Explanation
FB_WriteTrace Saves individual data or larger quantities of data
FB_ReadTrace Reads individual data or larger quantities of data
3.5.9.2 FB_WriteTrace
Individual values or large numbers of values can be temporarily saved in the FI with this FB. The values are
not permanently saved, i.e. the values are lost if the FI is restarted.
If the FB detects a positive flank on ENABLE, all parameters with are present on the input are adopted. The
value which is saved in VALUE is written to the memory address which is labelled by STARTINDEX and
MEMORY. If the writing process is successful, the output VALID is set to 1.
If the FB is now called up several times and the ENABLE input remains at 1, then with each call up of the
FB the input VALUE is read and saved and the memory address is increased by 1. The current memory in-
dex 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 saving process is stopped. However, if the OVERWRITE input is
set to 1, the memory index is reset to the STARTINDEX and the previously saved values are overwritten.
Values can be saved in INT or DINT format. For INT values only the Low part of the VALUE input is evalu-
ated. 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 5200 INT or 2600 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 101 FB_WriteTrace
VAR_INPUT VAR_OUTPUT
Input Explanation Type Output Explanation Type
ENABLE Execute BOOL VALID Writing process successful BOOL
SIZE Memory format BOOL FULL Entire memory is full BOOL
OVERWRITE Memory can be overwritten BOOL ERROR the FB has an error BOOL
MEMORY Selection of memory area BYTE ERRORID Error code INT
STARTINDEX Indicates the memory cell to
be written to INT ACTINDEX Actual memory index, to which sav-
ing will be carried out in the next
cycle DINT
VALUE Value to be saved DINT
ERRORID Explanation
0 No error
1A00h STARTINDEX value range exceeded
1A01h MEMORY value range exceeded