Instrumentation Systems & Services MicroSpeed 196 User Manual Download Page 10

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STATUS AND ALARM OUTPUTS:

Variable 18 - Drive Enable

This output is designed to give the MicroSpeed 196

control of the Run/Stop input on the controlled drive or other MicroSpeed 196 ’s,
based on the conditions it is monitoring. Drive Enable is actuated when

RUN or JOG

is pressed, and is deactivated automatically when

E-Stop is pressed, or upon loss of

power, thus disabling the drive. Drive Enable will perform one of the following
options when a normal STOP command is given.

The following options can be entered into Variable 18:

Variable 18 - 0001

The

Drive Enable

output waits for the Command Output

Voltage to reach 0V (zero) before disabling the drive.

Variable 18 - 0002

The

Drive Enable

output waits for the Command Output

Voltage to reach 0V (zero) and for the Feedback frequency to reach OHz (zero)
before disabling the drive.

Variable 18 - 0003

The

Drive Enable

output immediately disables the drive upon a

STOP command, and the Analog Output goes to zero (0) immediately.

Note: Disabling the drive prevents any motor creep or other unwanted motor movement
when the motor is stopped.

Variable 15 - High Alarm

This output is activated if the speed of the monitored

shaft exceeds the value programmed. When

High Alarm

is accessed, the alphanumeric

display will read

“Hi Alarm”

Enter the speed in user units above which the High

Alarm output will be activated.

Variable 16 - L

Alarm

This output is activated if the speed of the monitored

shaft drops below the level of the number entered in this variable. When the

Alarm is accessed, the alphanumeric display will read

“L

Alarm”.

Enter the speed

in user units under which the

Alarm

output will be activated.

Variable 17 - Deviation Alarm

This output is active in the Follower mode only,

and is programmed in revolutions of the follower feedback sensor. No decimal points
are allowed in this entry. The output will activate if the follower feedback sensor
deviates ahead or behind the lead shaft exceeding the programmed revolutions.

IX.

Tuning the MicroSpeed 196

Calibrating the Isolated Command Output to the Drive:

1. Program the MicroSpeed 196 variables.

Note: Variable 03 PPR must be programmed.

Select the proper polarity of the Command Output Voltage using the Forward/

Reverse Input. (Open = Positive; Closed = Negative)

3. Access Diagnostic 9 (Digital Potentiometer) by pressing 2nd Function key, then

the 9 key. The alphanumeric display will read Pot % 00.

4. Adjust the Zero Offset potentiometer (located on the back of the MicroSpeed 196 )

clockwise (or counterclockwise if reverse is selected), until the motor begins to
creep, then back off until it stops creeping.

5. Press and hold the (up arrow) key until the alphanumeric display reads

Pot % 90. The numeric display will be showing motor speed in RPM. Adjust the

Output Span potentiometer

(CW increases, ccw decreases) until the rpm displayed

in the numeric display is equal to the maximum rpm programmed in Variable 01.

Note: The drive and motor are set up to run at maximum speed while the MicroSpeed

196 is providing 90% Command Outputs, so that 10% Command Authority will be

available to compensate for slowdown caused by loading, etc., when the motor is

running at maximum set point.

Press and hold the

DOWN

arrow key until the alphanumeric display reads

Pot % 00.

7. Press

2ND FUNC

to exit the

Digital Potentiometer

mode.

FUNCTION AND TUNING OF THE PID VARIABLES:

The PID Variables make up the difference between the Expected Analog Output and
the Required Analog Output. The Expected Analog Output is based on a linear
relationship of 0-90% Command Output equal to 0 - 100% of the maximum speed
entered into Variable 01. The Required Analog Output is the actual Command Output
necessary to maintain the correct speed. A 0-100% Command Output is equal to
0-4094 DAC bits,

IMPORTANT!

Higher values in the PID Variables result in a faster correction time

and a tighter motor speed control. If the difference between the Expected Output and
the Required Output is extreme, the MicroSpeed 196 will begin changing its output in
the wrong direction, before the increasing error allows the PID Variables to overcome
this. Therefore, adjusting the output to the drive is very important.

PID VARIABLES:

Variable 12 - (P) Proportional (or Gain) -

Gain is the most active and important

tuning Variable. The Gain correction takes place every .0l seconds. A higher value
entered in this Variable (a number between 1 and 100) results in a faster change in the
Command Output to correct for error and, therefore, tighter motor control.