LS Industrial Systems GLOFA G7M-DT60U(N)/DC - Page 136

Chapter 7. Usage of Various Functions
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(6) Derivative time and integral time (%MW4806,%MW4807)
I_TIME and D_TIME are 10 times scaled up. The range of actual input is 0 ~ 20000.
(7) Mode command set
In GM7U, only the following 7 operation modes are available. Other operation modes, such as PD or I, are not
permitted.
No. EN_P EN_I EN_D PWM output Operation
1 1 (enable) 0 (disable) 0 (disable) P operation
2 1 (enable) 1 (enable) 0 (disable) PI operation
3 1 (enable) 1 (enable) 1 (enable)
0 (disable)
PID operation
4 1 (enable) 0 (disable) 0 (disable) P operation/PWM output
5 1 (enable) 1 (enable) 0 (disable) PI operation/PWM output
6 1 (enable) 1 (enable) 1 (enable)
1 (enable)
PID operation/PWM output
7 0 (disable) 0 (disable) 0 (disable) 0 (disable) On/Off operation
• If PWM output is selected, the calculated value is outputted with PWM.
(8) Set PWM
PWM (Pulse Width Modulation) is a output method which changes on-off duty of output pulses by calculated
manipulation value. The figure below shows an example of PWM output. Using PWM output, PID control system
can be constructed easily without D/A conversion module and power regulator. The output can be designated
when PWM is selected, but only main unit’s contacts can be used for PWM output. (The expansion module’s
output cannot be used.)
Ex.) Output range limit: 0~4000, operation scan time: 1s, PWM output contact: QX0.0.0
(9) SV Ramp
If a large amount of SV changes during PID operation, The deviation(E) changes rapidly. Then manipulation
value(MV) is changed rapidly also. This can cause damage on load or actuator. To prevent this situation, SV can
be changed step by step by parameter setting. Setting range is 1~4000(Default value is 1). Setting value
represents the number of time which taken from starting set value to last set value.
For example, if the operation scan time is set to 5 (0.5 sec), SV Ramp is 500, and SV changed from 1000 to
2000 during operation, it increases by 2 at every scan and reach 2000 after 500 scan time.
Time
MV = 2000
MV = 1000
0.5s
QX0.0.0
On
0.5s
0.25s
0.75s