Reading parameters
The following application example shows how the current voltage of the DC link can be read out.
- In MOVISUITE®, determine the index, subindex, and offset of the parameter to be read. To do so, move the mouse pointer over the parameter.
- The parameter properties are displayed in a tooltip.
- In this example, the value of the "DC link voltage – instantaneous value" parameter is read. The parameter has index 8364, subindex 160, and no offset.
- Send the required service (read parameter) and the values determined for index, subindex, and offset to the drive via process data. To be able to do so, "Bit 14: Activate service" must be reset in the control word of the parameter channel.
- Set "Bit 14: Activate service".
- For the duration of the service (50 – 200 ms), "Bit 13: Service active" is set in the status word of the parameter channel and "Bit 14: Service terminated" is revoked. After the service has been performed, "Bit 13: Service active" is revoked and "Bit 14: Service terminated" is set again.
- The result is displayed in the parameter channel status word "PI 4/5: Read data or error number". A successful execution of the service will lead to the display of the read value. An incorrect execution of the service will lead to the display of the error code (see chapter Error codes).
- In this example, the read value is 609635.
- As long as "Bit 14: Activate service" is set in the control word of the parameter channel, the result is displayed. If "Bit 14: Activate service" is revoked, "Bit 14: Service terminated" or "Bit 15: Error" is also revoked in the status word of the parameter channel and the read value is deleted.
The following cycle diagram shows the general process:
