Elmo DSP 402 User Manual

Page of 116
 
Data description: 
Value Description 
-32,768…-1 Manufacturer 
specific 
Linear ramp (trapezoidal profile) 
1 Not 
supported 
2 Not 
supported 
3 Not 
supported 
4…32,767 Reserved 
11.3   Functional Description 
Two different means of applying target positions to a drive are supported by this device 
profile: 
 
Set of set-points: 
After reaching the target position, the drive unit immediately processes the next target 
position
 that results in a move in which the velocity of the drive is not normally 
reduced to zero after achieving a set-point. 
 
Single set-point: 
After reaching the target position, the drive unit signals this status to a host computer 
and then receives a new set-point. After reaching a target position, the velocity is 
normally reduced to zero before starting a move to the next set-point. 
The two modes are controlled by the timing of the bits “new set-point” and “change set 
immediately
” in the controlword, and “set-point acknowledge” in the statusword. These bits 
allow a request-response mechanism to be set up in order to prepare a set of set-points 
while another set is still being processed in the drive unit. This minimizes reaction times 
within a control program on a host computer. 
The Elmo drive introduces a buffered mode (bit 13 in the controlword), in which up to 16 
subsequent profiled motions can be programmed. The programmed profiles are executed 
when the previous motion is target reached. In buffered motion, set-point acknowledge 
behaves in a manner similar to non-buffered mode, whereby the bit is reset when new 
data can be buffered. Using change set immediately interrupts the buffered motion. In this 
case, the buffer is reset and the last programmed motion is executed immediately. 
The sequence of a set new point is: 
1.  The host sends the trajectory data and validates it by setting the new set point. 
2.  The Elmo drive acknowledges reception and buffering of the new data by setting  
set-point acknowledge. 
3.  The host sends a command to start the first motion by resetting the new set point. 
4.  The motion begins. If the drive can accept more set points, the set-point acknowledge 
resets. 
CANopen DSP 402 Implementation Guide 
 
MAN-CAN402IG (Ver. 1.2) 
 
 
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