Delta RMC151 User Manual

Page 948

RMC70/150 and RMCTools User Manual

Because this parameter affects motion, the axis must be disabled or in Direct Output

before writing to this parameter. The Enabled and Direct Output Status Bits indicate these

states of the axis. When changing this parameter from RMCTools, the software will

automatically do this for you. This may cause a halt on the axis, which is expected.

Choosing the SSI Clock Rate

In general, choose the fastest clock rate possible to obtain the most accurate feedback

values. Before selecting the clock rate, verify that your encoder or transducer supports

the clock rate. Refer to your encoder documentation.
UI/O Module SSI Wire Delay
For SSI inputs on the UI/O module, wire delay compensation is available. If your cable

length exceeds the length for your clock rate given in the table below, you should use the

SSI Wire Delay parameter to account for the time delay of the SSI signal:

Clock Rate

Maximum Cable

Length*

100 kHz

2100 ft (640 m)

150 kHz

1360 ft (415 m)

230 kHz

850 ft (255 m)

250 kHz

770 ft (235 m)

375 kHz

475 ft (145 m)

500 kHz

325 ft (99 m)

921 kHz

120 ft (37 m)

971 kHz

110 ft (34 m)

* The cable lengths are approximate, and may be affected by the type of wire and

transducer.

Format Details

This section is primarily for addressing the SSI Clock Rate parameter when

communicating with the RMC from an external device. This information is not necessary

when configuring the SSI Clock Rate in RMCTools.
The SSI Clock Rate is selected with bits 10-11 in the MDT/SSI Configuration Register.

These bits correspond to the SSI Clock Rate as shown in the table below. The RMC150

clock rate is not selectable, and the bits should be zero.

RMC70 MA Module

Bit

SSI Clock Rate