Specifications

Applications Ver. 0002 AP - 5
These parameters and the way to calculate them are also applicable to generate the digital
Sercos velocity command.
This command is transmitted through fiber optics in motor rpm.
This command conversion from a mV to a digital command requires some parameters to be
sent at the CNC as well as at the Drive. The following sections show how to se them.
AP.1.1.2.1 On Axis drives
The CNC communicates to the Drive and through the Sercos ring the desired motor speed in
rpm (MS) calculated as follows:
NP121 -S00121-, NP122 -S00122- and NP123 -S00123- are parameters of the drive.
Thus, for a proper setup of the system, proceed as follows:
At the drive:
- Set parameters NP121, NP122 and NP123 according to the gear ratios installed.
- SP20 -F00031- and SP21 -F00081- are ignored.
At the CNC:
- Set MAXVOLT = 9500 that is: 9.5 volts.
- Calculate the PROGAIN constant based on a command of 9500 mV. Thus:
where:
EdS (mm) = following error at G00FEED.
Kv is a constant indicating the ratio between G00FEED and the EdS. Thus:
for Kv=1, the EdS (following error) will be 1 mm for a feedrate of 1 m/min.
for Kv=2, the EdS (following error) will be 0.5 mm for a feedrate of 1 m/min.
Feedback parameter setting at the axis drive:
With SERCOSLE=0
Using external feedback requires that all the feedback parameters to be set at the CNC:
PITCH (P007), NPULSES (P008), DIFFBACK (P009), SINMAGNI (P010),
FBACKAL(P011), REFPULSE (P032), IOTYPE (P052), ABSOFF (P053) and
EXTMULT (P057). They are located in the parameter table for each axis a the 8050/55
CNC.
With SERCOSLE=1
The Drive indicates the motor speed to the CNC 50/55 by means of digital commands
through Sercos. Therefore, the feedback characteristics will be set by the parameters of
the Drive. At the CNC 50/55, the parameters mentioned earlier are ignored.
PROGAIN
9500
EdS
9500 Kv 1000
G00FEED
(mV / mm)==
⋅⋅
[]
MS f PROGAIN,FFGAIN...
mV
G00FEED
MAXVOLT
1
NP123
NP121
NP122
(
rpm motor
)
××
12444 3444