7344 blending behavior question

[lob]

I've noticed sometimes when doing a series of blended moves the first move in a sequence will have some (seemingly) random velocity, usually slow, and the rest will all be correct. Before the first flex_load_vs_position() and flex_blend() is called, all parameters are setup for the blending using:

flex_config_vect_spc()
flex_load_acceleration()
flex_load_velocity()
flex_set_op_mode()
flex_load_blend_fact()

with the velocity/acceleration/blend factor (-1)/etc that is desired. As mentioned, all the vectors AFTER the first one always work correctly, it is the initial move that sometimes is the wrong velocity. I'm thinking that this has something to do with calling flex_blend() for the first move, as some examples i have seen call flex_s
tart() for the first move. I have tried this, but same random first velocity behavior results. Must be some kind of buffer that is not flushed out properly for the trajectory math to work or something?

[nestor-sg]

It sounds odd that with Start at the beginning will give you the same behaviour. Please check the example name 'Sequence of One-Axis Moves' that is shipped with the software for CVI or LabVIEW. It is going to be in the ...\samples\ directory of CVI or \examples\ directory in the case of LabVIEW.

You can also start with a simple move example, using start, and then include one Blend sequence afterwards to see if you can reproduce the issue, it might be possible that you are calling other routines at the same time or one that is overwriting the Velocity and Acceleration values. In the order of functions call the Blend Factor after configuring the Vector Space, then set the operation mode, and finally load Accel/Deccel and Velocity parameters.

Good luck!

Nestor.