DFRFG, ramp time

Question:

What is the ramp time in the DFRFG if it is only determined by the offset?

Answer:

If the ramp is solely determined by the DFRFG1 offset (acceleration time set to 0.001 seconds), the following formula applies:

• Ramp time = 2 * offset / speed

Example:
Given: C0011 = C0752 = 3000 rpm, C758 (offset) = 65536 Inc
t = 2 * 65536 / (50 1/s * 65536)
t = 2 / 50 s
t = 0.04 s

In a real application one must bear in mind that the maximum current limit (torque limit) will not be reached.

Further information:

• The ramp time set in C0751 always relates to C0011.
• The maximum speed set in C0752 indicates the maximum attainable output speed of the function block.

URL for linking this AKB article: https://www.lenze.com/en-de/go/akb/20020065/1/