NORD Drivesystems BU0090 - Manual (Page 42)

NORDAC AS-Interface Manual
42 BU 0090 GB
5 Data transfer / Parameter-string transfer
NOTE
The information in Section 5 does not apply to the AS interface Technology Unit SK TU2-AS3
(A/B slave).
(only necessary for extended functionality)
The Parameter string transfer is available for the modules SK TUx-AS1 (Standard slaves, slave profile
S-7.4). This extended functionality is implemented in the AS interface master according to the Complete
Specification
2.1. With this, direct communication and transfer of parameter data to the AS interface slave can
be simply realised. In contrast to the data transfer from the sensors (cyclical processing), the string transfer is
carried out acyclically. Therefore the transfer of parameter strings takes considerably longer than the cyclical
exchange of 4I/4O data.
By means of the functions "write parameter" and "read parameter", parameters in the frequency inverter can
be changed or read out by the application control program. Three string reading commands and a string writing
command are available:
• Read ID string -Inverter and AS interface version information and identification
• Read diagnosis string -Signal statuses of the I/Os, process data and if necessary, inverter error no.
• Read parameter string -Read out the parameter values of the frequency inverter
• Write parameter string -Write the parameter values of the frequency inverter
The following sections provide information on the available commands.
NOTE
It should be noted that with continuous parameter string transfer and certain interface-bus
configurations, the cyclical data exchange (every 5ms) to and from the sensors is suppressed!
Due to the specified AS system behaviour, this condition cannot be avoided by NORD as
manufacturers of the device. This system behaviour must therefore be taken into consideration
when programming the control unit and the use of the parameter string transfer functionality.