IL•1F CANopen DS301 | 6 Operation |
0198441113586, V2.01, 11.2008
6.4Examples for the operating modes with PDO4
R_PDO4 With the R_PDO4 you can start motion commands and change them while they are being processed.
R_PDO4 provides three fields for these purposes:
•modeCtrl Starting and changing operating modes
•"Ref16" and "Ref32" Operating
The specified values for these three fields are not taken over by the prod- uct until modeCtrl, bit 7 (ModeToggle) changes.
Proceed as follows to assign values to the product:
Enter the desired operating mode and the corresponding values in the fields modeCtrl, "Ref16" or "Ref32".
Change modeCtrl, bit 7 (ModeToggle)
This avoids consistency problems within the R_PDO4.
T_PDO4 T_PDO4 allows you to monitor motion commands.
T_PDO4 provides three fields for this purpose:
•modeStat For Handshake purposes
•driveStat Signals motion status and errors
•p_actActual position of the product
ModeToggle The bit ModeToggle is available in the R_PDO4 and in the T_PDO4. The master provides this bit in the and the product mirrors is in the . This pro- cedure allows the master to detect whether the data transmitted by the slave is current.
Example The master starts a positioning movement that will only take a very short time. The master waits for the end of the positioning movement by checking T_PDO4 for bit x_end = 1 (positioning end).
The master may receive data from the slave that still originate from a point in time before the positioning movement was started. This data also contains x_end = 1. The master detects that the data is obsolete because the included bit ModeToggle does not match that of its motion command.
The master may only evaluate data in which the received ModeToggle bit is identical to the last bit transmitted by the master.
Acceleration Prior to positioning, you can first set the desired acceleration with an SDO access (object Motion.acc, 29:26). Note that the acceleration can only be changed when the product is at a standstill.
Assumptions The examples in this chapter are based on the following assumptions:
•Operating state 6 "Operation Enable"
•Homing has not yet been performed (bit ref_ok = 0)
•p_act = 0 (actual position)
•R_PDO4: modeCtrl, Bit 7 = 0 (ModeToggle)
Fieldbus interface | 67 |