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Extracting absolute position from the drive, Extracting absolute position from the drive -20 – Rockwell Automation 2092-DAx Ultra1500 User Manual User Manual

Page 100

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Publication 2092-UM001D-EN-P — July 2005

5-20

Ultra1500 Application Examples

Extracting Absolute Position from the Drive

The absolute position of the Ultra1500 can be extracted via the encoder
outputs on pins 29 through 32 of connector CN1 using a digital input of the
drive to request the transfer. Refer to See Figure 5.1 on page 5-2 for an
example of this using the 1756-M02AE Analog Encoder Servo Module.
A digital output of the controller must be connected to one of the general
purpose inputs of the drive. (If the PLC digital output is active high, it must be
converted with an external circuit to active low to properly drive the Ultra1500
input.) This digital input must be assigned to have Position Strobe
functionality:

The active-going transition (an active state is when the opto-isolator is turned
ON and the input voltage is 0V) of the Position Strobe input starts a
time-based sequence in which the absolute position data is transferred via the
A and B encoder outputs of the drive, as shown in Figure 5.6.

Figure 5.6
Ultra1500 Absolute Position Extraction Timing Diagram

Position

Strobe

AqB

Encoder

Outputs

Outputs Held

Outputs Held

Outputs Held

100 mS

Delay

100 mS

Delay

50 mS

Delay

Multi-turn revolution data

0 to 66 mS

Fractional revolution data

0 to 132 mS

Normal Encoder

Output

Normal Encoder

Output

1 MHz

Frequency

1 MHz

Frequency