Moog MSD Servo Drive Series User Manual

SSI wire break monitoring (bit monitoring during monoflop time)
If monitoring is enabled, the drive, as the SSI clock master, will read data for one
more clock cycle after the data bits (reading data after the data bits end is
permissible). The bit that the master reads in addition to the data bits this way comes
from the SSI encoder’s monoflop time. At the time corresponding to this bit, the SSI
encoder must drive the data lines with a logic 0. If the data lines on connector X8 are
open, a logic 1 will be read here. The bit monitoring at this point makes it possible to
determine whether the SSI data lines are being actively driven with a logic 0 at this
point (no “wire break”) or are not (“wire break”). SSI wire break monitoring can be
disabled by setting P576[0] - ENC_CH3_Modeto0001h.
Mode parameters and CycleCount parameters
P576[0] - ENC_CH3_Mode can be used to run a parity evaluation after the data. In
addition, ENC_CH3_Mode makes it possible to run special SSI encoders that deliver
one or more special bits after the data. In this case, the MSD Servo Drive will not
evaluate these bits – this mode is meant to make it possible to work with SSI
encoders that require for these bits to be sampled. P636[0] - ENC_CH3_
CycleCount makes it possible to run slower SSI encoders that cannot handle the
required cycle of 125µs. The control characteristics will deteriorate when using this
type of SSI encoder, which is why doing so is not recommended.
ID Index Name Unit Description
507 ENC_CH3_Sel=2 =SSI(2)
573 0 ENC_CH3_MultiT NumberofMultiTurnbits(absoluteencoder)
574 0 ENC_CH3_SingleT NumberofSingleTurnbits(absoluteencoder)
575 0 ENC_CH3_Code Codeselection(SSIabsoluteencoder)
576 0 ENC_CH3_Mode Modeselection(SSIabsoluteencoder)
584 0 ENC_CH3_MTBase MinimumMultiTurnposition(SSIabsolute
encoder)
585 0 ENC_CH3_MTEnable Channel1:Multi-turnassingle-turn
600 0 ENC_CH3_Position inc Positionencoderchannel1
636 0 ENC_CH3_CycleCount Channel3:Positionencodersamplingcycle(nx
125µsec)
Table 6.25: Encoder configuration channel 3 (X8) - SSI parameters
MOOG
ID
No.: CB40859-001 Date: 02/2018
MSD Servo Drive- Device Help
86
6 Encoder
The Sel, Lines, MultiT and SingleT parameters are self-explanatory.
Other parameters, such as MTBase and MTEnable, are described elsewhere
(see Section "Channel 3: Interface X8 (optional)" on page 74 and the Section "Sin/
Cos/ TTLX8" on page 81).
NOTE
 LinearSSIencoderswillbetreatedasrotarySSIencoders.Inthis
case,itisimpossibletodeterminethatthesystemisalinear
encodersystembasedontheencoderhead.
 P 573[0] - ENC_CH3_MultiT=Numberofmulti-turnbits:0..14
DuetothedesignofthecyclicalSSIinterfaceasamotorfeedbackinterface,
thenumberofmulti-turnbitsislimitedto14(nolimitto14bitsinthecaseofa
Sin/CosinterfacewithSSIone-timereading).
 P 575[0] - ENC_CH3_Code=SSIdecoding:BINARY(0)orGRAY(1)
Graydecodingwillbeselectedbydefault.Theotheroptionistousebinary
decoding.
 P 576[0] - ENC_CH3_Mode=AvailableSSIauxiliarysettings
Thisparameterhasa16-bithexvalue.Withthedefaultsetting(0000h),SSI
wirebreakmonitoringwillbeenabled.Avalueof0001hwilldisableSSIwire
breakmonitoring,meaningthatonebitlesswillberead.
Followingisalistofwhatsomeofthetermsinthetablebelowstandfor:
o
Data=Sequenceofalldatabits
o
EncObs=Wirebreakbit
o
Nothing=Nobit
o
POdd=Oddparitybit
o
PEven=Evenparitybit
o
Free=Afreebit

Moog MSD Servo Drive Series Specifications

General

Brand	Moog
Model	MSD Servo Drive Series
Category	DC Drives
Language	English