NORD Drivesystems BU0280 - Manual (Page 35)

4 Commissioning
BU 0280 GB Subject to technical amendments 35
4 Commissioning
The DeviceNet module is a slave with “Group 2 Only Server” properties. Devices of this type can set up the
following pre-defined connections:
 Explicit Request/Response Message (Parameter Transfer)
 Several static I/O messages (fragmented)
 Polled I/O connection
 Bit-Strobe I/O connection (gateway operation is only possible to a limited extent in this mode)
The transfer rate for parameter access (requested message body format) is 8/8 (8 Bit Class ID / 8 Bit Instance
ID).
Clients which wish to use the gateway function of the DeviceNet must support fragmented transfer of the I/O
messages.
4.1.1 Gateway function
Up to four FIs and the bus module can be controlled via the bus module.
With "explicit messages transfer", the differentiation of the FI is carried out via various classes (see Section
"DeviceNet Communication”).
A single telegram is sent for the I/O messages (process data). This telegram contains the process data for all
four FIs and the bus module. With several FIs on the system bus, the data length exceeds the available 8
bytes, i.e. in gateway operation the data must be fragmented.
The required data size and its allocation to the individual FI is made in the module parameters (P160) to
(P165). These parameters are stored in an EEPROM in the module. The exact allocation is explained in the
section "DeviceNet Communication".
4.1.2 Parameterisation via DeviceNet
All modules and FI parameters can be accessed via DeviceNet. This is carried out via Class 100 to 181.
If parameters are accessed for FIs which are not connected, the bus module responds with the error message
“Resource unavailable”.
4.1.3 Timeout monitoring
Data traffic on the DeviceNet side is monitored via various timeouts defined by DeviceNet and/or P151.
P151 monitoring is triggered if the process data contact is interrupted or the process data in the USS profile
are transferred with an invalid control word. Transfer of process data with a data length 0 (PLC in programming
mode) also results in an error.
Sending of BitStrobe telegrams causes a reset of the P151 function, although no new process values have
been sent.
Parameter P513 is not evaluated in the bus module. The error behaviour of the individual FI can be defined via
this.
4.1.4 Input filtering
The four inputs are cyclically read every 250µs. This data is input into a filter routine. The minimum time for a
change of flank is 1ms.