Delta MMC120 User Manual

Page 68

transducer count between interrogations changes too much (indicating noise), red LED 3

or 7 will be latched. Check the transducer power supply and check the wires to the

transducer.

Red LEDS 2 and 6 are on; all other red LEDS are flashing; no green LEDS

This indicates that the flash memory on the module has an invalid checksum. You must

download a new copy of the firmware to the module.

During a move, the Actual Position is erratic

Electrical noise or a defective transducer is usually the cause of this problem. Monitor

bits 1, 2, and 3 of the axis’s

STATUS

word to determine if the module is detecting a

transducer error. To reduce electrical noise check the following:

1. Make sure the transducer wiring is separated from all other wiring.
2. Add a termination resistor (220 ohm for Temposonics I) as close to the transducer as

possible.

3. Connect the shield at the module end, the transducer end, or both.

During a move, the drive comes to a halt for no apparent reason

When the module detects a 'transducer not responding' error it makes a Hard Stop. See

'Actual Position is erratic' above for more information. If any of the following conditions

are enabled, the axis will also halt:

Following Error
Overdrive Error
Position Overflow
Parameter Error
Integrator Windup

Transducer counts field not indicating transducer location

See “Red LEDS 2, 3, 4, 6, 7, or 8 are on” above.

Transducer counts field changes but output drive does not work

See “During a move, the drive comes to a halt for no apparent reason” above.

The System is unresponsive and hard to tune

This problem could have several causes. The first items to check are:

1. Is there hose, rather than rigid pipe, installed between the hydraulic valve and the

cylinder? The hose expands and acts like an accumulator and the fluid goes to fill the

hose rather than move the cylinder.

2. Does the valve have overlap? Overlap in hydraulic valves causes a significant dead

band and slows the system response. Some proportional valve amplifier cards have