CANopen Technical Guide | ASDA-A2 3.2 Interpolation Position Mode 3.2.1 Description The Host sends a broadcast SYNC frame (0x80) cyclically. With each PDO, the Host sends the next reference position Xi, the difference △ X i and controlword to the drive. While the next SYNC receiving, the drive interpolates from X i-1 to X i . There is no input data buffer, which will cause delay. Extrapolation, Jitter Compensation When SYNC object is delayed, the interpolator should generate with the last acceleration and extrapolate predicted speed and position. When the SYNC delays for 2*cycle, Drive should stop and send out an error message.
PDO Rx/Tx Mapping record PDOs from Host to Drive - 32 bit reference position [position increment] - 16 bit symmetrical difference [increments] △ X i = (X i+1 – X i-1 )/2 (it is also the same as velocity) - 16 bit control word. PDO from Host to Drive (Every PDO contain 8 bytes field like below) 3.2.2 Operation Procedure ① Set 【 Mode of operations:6060 h 】 to interpolation position mode(7). ② P1-01 = 0x0B, Set 【 Interpolation sub mode select:60C0 h 】 to Interpolation mode. If 60C0 h is [0] or [-1], Host needs to send [60C1h Sub-3] and Drive will work more precisely. If 60C0 h is [-2], Host does not need to send [60C1h Sub-3].
It could save calculating time of Host and Drive could work also. P1-01 = 0x0C, Set 【 Interpolation sub mode select:60C0 h 】 to Interpolation mode. If 60C0 h is [0], Host does not send [60C1 h Sub-3]. It could save calculating time of host If 60C0 h is [-1], Host need to send [60C1 h Sub-3] and Drive will work more precisely. and Drive could work also. ③ P1-01 = 0x0B, Set 【 Communication Cycle period:1006 h 】 to predict SYNC interval. The unit of this object is microsecond. It is recommended to set this value for a multiple of 1000 microsecond. Revision Sep, 2012 16 32 bit reference position 16 bit difference 16 bit controlword