User manual

Publication 2092-UM001D-EN-P — July 2005

2-22 Ultra1500 Connector Data

Figure 2.22

Motor Encoder Outputs

Index Pulses

The Ultra1500 has two separate differential outputs that provide an index

pulse for use with controllers. In the case of a rotary motor with a serial

encoder, the marker pulse is generated in the drive hardware.

• The differential buffered encoder output, Channel IM+ and Channel IM-

(CN1-33 and CN1-34), provide a buffered version of the encoder marker

pulse. As with the AM and BM channel outputs, the time duration of the

signal states depend on the rotational speed.

• The Z-Pulse differential outputs, (CN1-17 and CN1-18), provide an

opto-isolated marker signal that has a minimum time duration of 800 µsec.

At low speeds, the two marker outputs are identical, however at high

speeds the Z-pulse output will enforce a minimum time duration of 800

µsec.

On incremental motor encoders, the index output (IM+ and IM-) is a buffered

version of the encoder index, and it is not altered. However, the AM and BM

signals are both inverted from the encoders signals. If the controller requires

non-inverted AM and BM outputs (e.g., if the controller gates the index with a

particular AM/BM state), the + and - signals of the AM and BM outputs can

be swapped before connecting to the controller.

With serial encoders, the index output (IM+ and IM-) is generated by the drive

hardware, since the serial encoders do not have an actual index signal. The

generated index signal is two counts in width, and phasing to a particular A/B

state is arbitrary. The index signal is generated at the zero location of the

fractional revolutions for the encoder.

AM-

AM+

75174

16V16V

Logic Ground Logic Ground

Ultra1500 Drive

AM, BM, and IM Outputs

Z-Pulse-

TLP127

330 Ω

Z-Pulse+

0.5A Fuse

Logic Power

Ultra1500 Drive

Z-Pulse Output