Lenze Function library CANopenSdoDrv - Manual (Page 10)

Function library "CANopenSdoDrv"
Function blocks
IndexRead - read CAN index
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L
DMS 1.0 EN - 07/2011 - TD05
4.1 IndexRead - read CAN index
This FB serves to read parameters (CAN indexes) of other devices via system bus (CAN). The
block uses the reduced SDO upload ("expedited transfer").
 nAddress serves to select the corresponding node where the SDO access is to take place.
At the same time, the parameter channel to be used (SDO1 or SDO2) is selected at the
node via nAddress.
Call possible in: ; Cyclic task
Interrupt task
; Time-controlled task (INTERVAL)
Event-controlled task (EVENT)

Note!
• The FB must be called cyclically in order that the response to the write request
("read response") is detected. Typically, the response arrives only some
program cycles later.
• Make sure that several nodes do not execute an SDO access a node at the
same time via the same parameter channel, since this "collision" would cause
the system bus (CAN) to change to the "bus off" status.
• Do not start several SDO accesses to the same node at the same time. This
causes an incorrect evaluation of the node response.
• Do not use the FBs from the "CANopenSdoDrv.lib" library and the FBs
L_ParWrite and L_ParRead from the "LenzeDrive.lib" library at the same time.
IndexRead
⎯ bExecute bDone ⎯
⎯ nAddress bBusy ⎯
⎯ nIndex nIndexSize ⎯
⎯ nSubIndex dnValue ⎯
⎯ tRxTimeout bError ⎯
dnErrorNo ⎯