Emerson SI-Universal User Manual page 59

1x.033
Minimum
Default
Type
Display Format
Coding
P1 Rotary Turns Bits (1x.033) only has any effect if the position feedback interface is being used
with a rotary device (i.e. P1 Linear Feedback Select (1x.051) = 0).
P1 Device Type (1x.038) : SC Hiperface, SC EnDat, SC SSI, EnDat, BISS*, SC BiSS*, SSI
P1 Rotary Turns Bits (1x.033) is used to determine the number of bits within the comms messages
from the position feedback device that represent turns. For a single turn encoder P1 Rotary Turns
Bits (1x.033) must be set to zero. It should be noted that some SSI encoders include leading zeros
before the turns information, and in this case the number of turns bits should include the leading
zeros. The most significant bits in P1 Revolution/Pole Pitch Counter (1x.028) that are not included
in the turns information provided by the encoder comms are held at zero. If P1 Rotary Turns Bits
(1x.033) = 0 (single turn encoder) the whole of P1 Revolution/Pole Pitch Counter (1x.028) is held at
zero. The number of bits of position information for a rotary device are calculated from P1 Rotary
Turns Bits (1x.033) and P1 Comms Bits (1x.035). If the resulting value is greater than 32 it is limited
to 32. Some BiSS encoders include leading zeroes before the single turn position or the multi turn
position, therefore P1 Rotary Turns Bits (1x.033) should include the number of leading zeroes.
(See 1x.038).
P1 Device Type (1x.038) : Any other device type
It is sometimes desirable to mask off the most significant bits of P1 Revolution/Pole Pitch Counter
(1x.028), but this does not have to be done for the drive to function correctly. If P1 Rotary Turns Bits
(1x.033) = 0 the whole of P1 Revolution/Pole Pitch Counter (1x.028) is held at zero. If P1 Rotary
Turns Bits (1x.033) has any other value it indicates the number of bits in P1 Revolution/Pole Pitch
Counter (1x.028) that are not held at zero. For example, if P1 Rotary Turns Bits (1x.033) = 5, then
P1 Revolution/Pole Pitch Counter (1x.028) counts up to 31 before being reset.
1x.034
Minimum
Default
Type
Display Format
Coding
P1 Rotary Lines Per Revolution (1x.034) only has any effect if the position feedback interface is
being used with a rotary device (P1 Linear Feedback Select (1x.051) = 0).
P1 Device Type (1x.038) : AB, AB Servo
P1 Rotary Lines Per Revolution (1x.034) should be set to the number of lines per revolution for the
encoder connected to the P1 position feedback interface.
P1 Device Type (1x.038) : FD, FR, FD Servo, FR Servo
P1 Rotary Lines Per Revolution (1x.034) should be set to the number of lines per revolution for the
encoder connected to the P1 position feedback interface divided by 2.
* BiSS is not currently supported.
SI-Universal Encoder User Guide
Issue: 2
P1 Rotary Turns Bit
0
16
8 Bit User Save
None
RW
P1 Rotary Lines Per Revolution
1
4096
32 Bit User Save
None
RW
Maximum 16
Units
Background read, auto-
Update Rate
configuration write
Decimal Places 0
Maximum 100000
Units
Background read, auto-
Update Rate
configuration write
Decimal Places 0
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