3 description of the timing diagram, Description of the timing diagram – Festo Контроллеры двигателя CMMS-ST User Manual
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4. Functional safety engineering
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Festo.P.BE-CMMS-ST-G2-HW-EN
1008NH
4.3.3 Description of the timing diagram:
This timing diagram is based on the example of speed regulation using the controller
enable DIN 5 at [X1]. For Fieldbus applications, the controller enable is additionally
controlled via the respective Fieldbus. Depending on the application, the operating mode
is also parameterisable via the parameterising software.
Starting state:
- The 24V supply is switched on and the intermediate
circuit is charged.
- The controller is in the ”Safe standstill” status. This state
is indicated by a flashing ”H” on the 7-segment display.
In order to switch the controller end stage active once more, and thus operate the
connected motor, the following steps must occur:
1. The relay control for switching the end stage driver power supply (2nd switch-off
path) must be supplied with 24V between pin 2 and pin 3 of [X3] at time t1.
2. The driver supply is then charged.
3. The potential-free feedback contact ([X3] Pins 5 and 6) for plausibility checking of the
driver supply relay control opens a maximum of 20 ms after t1 (t2-t1) and the driver
supply is switched off.
4. Approx. 10 ms after the acknowledgment contact opens, the ”H” on the display goes
out at time t3.
5. The time for the end stage enable ([X1], DIN4) is largely freely selectable (t4-t1). The
enable may occur at the same time as the relay is controlled, but it must occur
approx.10 祍 (t5-t4) before the rising edge of the controller enable ([X1], DIN5),
depending on the application.
6. The rising edge of the controller enable at time t5 releases the motor holding brake
(if present) and the end stage enable occurs. The brake can only be released when
the relay for switching the driver supply is engaged, since this controls a MOSFET in
the holding brake circuit. Using the parameterising software, a travel start delay time
(t6-t5) can be set that regulates the drive at a speed of ”0” for the specified time
and, after this delay, causes it to move at the set speed at time t6. The travel start
delay time is set to ensure that the brake has actually released before motion
begins. For motors without a holding brake, this time can be set to 0.
7. At time t7 the drive has reached the set speed. The requires ramp settings can be
parameterised using the FCT parameterising software.