Datasheet

The higher “P” is set, the noisier the motor will be when stopped. This is because higher gain causes more vigorous dithering
between encoder counts at rest. There is a trade-off between high gain (high stiffness) on one hand and excessive dithering
(noise and motor heating) on the other.
The “I” setting takes out the remaining following error. Increasing the “I” setting will increase the servo stiffness; if it is
increased too much the servo will oscillate.
To see how a servo is compensated it is first necessary to induce a disturbance. The easiest way is to switch the DIRECTION
input while commanding a constant speed via the STEP input. The abrupt direction change puts a momentary load on the
motor while the oscilloscope shows how it responds (see oscilloscope traces above).
If you are using an oscilloscope, use channel 1 on TP1 and channel 2 on the DIRECTION input. Set the trigger to “normal”,
trigger source to channel 2 and trigger edge to “+”. You should see a single sweep for every clockwise change in direction.
CURRENT LIMIT
The current LIMIT trimpot sets maximum continuous current the motor is permitted to have. It is adjustable from 0 amps to 20
amps. The trimpot setting is proportional to current; if it is set to full scale it will be outputting 20A, half scale will output 10A,
quarter scale will output 5A, and so on. The trimpot will be full OFF (0A) when it is turned all the way clockwise, and will output
full power (20A) when it is turned fully counter clockwise.
The behavior of the trimpot is controlled by DIP SW 7. If SW 7 is off, the G320X will limit the current to the trimpot setting until
it runs into an excessive load. It will then start a 1 second timer and limit the current draw to 20A; if it does not overcome the
load it will limit at the trimpot set current. The load must drop below the trimpot setting to reset the timer. If SW 10 is on
(default), the G320X will constantly output what the LIMIT trimpot is set to. Normally the LIMIT trimpot is set to the motor’s
continuous rated current.
INDICATOR LEDs
The G320X has four indicator LEDs. These are:
IN-POSITION indicator (IN POS Green LED)
WARN indicator (WARN Yellow LED)
FAULT indicator (FAULT Red LED)
POWER indicator (POWER Green LED)
The FAULT indicator (red LED) is on while the drive is in power-on reset, the DISABLE input is held “low” or if the protection
circuit is tripped due to a FAULT condition. All output switching stops are reset. The FAULT condition lasts for 1 second, and
then self-resets to try again. If the G320X enters a FAULT condition it will dynamically brake the motor. This means if a FAULT
occurs while the motor is moving the motor will very rapidly decelerate to a stop.
There are three conditions that will trip the protection circuit. One condition is a short-circuit. The second condition is if there is
no encoder attached; the G320X detects if one or more encoder wires are not connected. The third condition is if the POSITION
ERROR exceeds the set following error limit. This condition can have several causes:
1) The loop settings are severely under-damped and the motor breaks out into oscillation.
2) Excessive motor load due to acceleration or workload.
3) The speed command in excess of what the motor can deliver.
4) The current LIMIT is set too low.
5) The power supply current is insufficient for the demand.
6) The power supply voltage is below 18 VDC.
7) The motor is wired backwards, is broken or disconnected.
8) Encoder failure.
The IN-POSITION indicator (green LED) is lit when the motor is within 2 increments of motion of the commanded position. If the
motor is out of position by more than two increments of motion the indicator will not be lit.