spindle gearbox

Hy there,
I have a spindle with a gearbox , so there are two speeds, changed by an hydraulic cylinder.
Did someone had something like it? I have enough experience with PLC programming , but there
is a typical problem with the gear shift , and that is usually necessary to oscillate very slightly
forward and backward motor spindle to fit the gear pinion. For example, the Fagor CNCs can generate
a few AC millivolts on the spindle setpoint . I'd like to use CL regard to experience but for the analog
output I already have a 5i23+7i48... so if HAL takes control over 7i48 spindle analog output, I can't see
how to send the oscillating value. May be there's a possibility sending the setpoint to CL, manage with
the signal and send it back to 5i25+7i48, but I tested that CL is a bit slow refreshing modbus TCP I/O (0.1---0,3sec),
and be afraid to get the same delay while controlling the spindle, making it unusable for things like threading.

Very thanks in advance, mario.

It seems like that could be done all in the HAL file by using a combination of the scale and siggen components.

The siggen component can generate a sine wave signal thats added via the scale component
to the spindle control output. The amplitude of the oscillation can be set via the siggen's amplitude
(so it can be disabled when in normal operation)