NORD Drivesystems BU0550 - Manual (Page 52)

PLC logic for NORD SK 54xE frequency inverters
52 BU 0550 GB-0813
3.5.2.1 MC_ReadParameter
Reads a parameter cyclically from the frequency inverter as long as ENABLE is set to 1. The parameter
which is read is saved in Value and is valid if DONE is set to 1. For the duration of the reading process the
BUSY output is set to 1. If ENABLE remains set to 1, the parameter is read out cyclically. The parameter
and the index can be changed at any time if ENABLE is active. However, it is difficult to recognize when the
new value is read out, as the DONE signal is always set to 1. In this case it is advisable to set the ENABLE
signal for a cycle of 0, as then the DONE signal will be reset. The parameter index results from the index in
the documentation minus 1 (see Table 70). For example P700 Index 3 ("Reason for switch-on block") is
queried via the parameter index 2. In case of error, ERROR is set to 1. In this case, DONE is 0 and the
ERRORID contains the error code. If the ENABLE signal is set to 0, all signals and the ERRORID are
deleted.
Table 71 MC_ReadParameter
VAR_INPUT VAR_OUTPUT
Input Explanation Type Output Explanation Type
ENABLE Enable BOOL DONE Value is valid BOOL
PARAMETER NUMBER Parameter number INT BUSY The process is not complete BOOL
PARAMETER INDEX Parameter index INT ERROR Reading has failed BOOL
ERRORID Error code INT
VALUE Parameter read out DINT
ERRORID Explanation
0 Invalid parameter number
3 Incorrect parameter index
4 No array
201 Invalid order element in the last order received
202 Internal response label cannot be depicted