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NORD Drivesystems BU0550 User Manual

Page 52

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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