Eurotherm 590SP, Руководство по эксплуатации продукта

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590SP Digital Product Manual
App. M - 31
Appendix M Special Blocks and Application Notes
M
Input Signal Descriptions
This section describes the functions of the terminals used in the SC configuration.
WARNING
The control terminals of the drive are fully isolated from all power circuits and should not be connected
to other non-isolated circuits. In the interests of safety and to minimize electrical noise, it is
recommended that the drive 0 volts common terminal be connected to ground either directly at the drive
or at one point in the system.
Draw/Ratio
The draw/ratio signal is connected to terminal A2. It should read +10 volts for maximum draw or ratio. The CALI-
BRATION parameter for terminal analog input 2 can convert the input signal to the desired output range, 5 percent
maximum draw for example.
Line Reference
A line speed reference is required because the feedback device provides only a speed trim signal. It should be scaled to
+10 volts at full speed and connected into terminal A4, LINE SPEED REFERENCE. The 5703 Peer-to-Peer commu-
nications unit may alternatively be used for a digital line reference.
Tension Setpoint
The tension setpoint of 0 to +10 volts (scaled internally using CALIBRATION) connects to terminal A5, TENSION
SETPOINT. Typically this signal comes from a potentiometer supplied from the drive's +10 volt terminal, B3.
For dancer position applications, this input is not required. The user can enter the setpoint directly in the MMI in pa-
rameter SPECIAL BLOCKS:: PID:: INPUT 1 if terminal A5 is connected to a DESTINATION TAG other than 410.
The setpoint will normally be set at the same value as the feedback signal with the dancer positioned midway between
stops, for example if the feedback range is 10 to 90 percent, the setpoint would be 50 percent.
Tension Feedback
The tension feedback signal from a loadcell must be scaled using a loadcell amplifier, such as the Eurotherm Drives
5530/1 or 5530/2, before connecting into terminal A6, TENSION FEEDBACK, on the 590SP. At full tension, the out-
put should be adjusted to read +9 volts to allow 10 percent overrange.
The dancer position is the tension feedback in dancer applications. The dancer uses a position transducer with a signal
range of 0 to +10 volts. The simplest type of transducer is a potentiometer coupled to the dancer shaft and supplied
with +10 volts by the drive's terminal B3. The optimum mechanical arrangement provides nearly full potentiometer
rotation for the full dancer travel. At the cost of resolution, less rotation is acceptable down to a minimum of about 30
percent or 3 volts change.
Reverse
Reverse, terminal C6, changes the direction of the line section. It is connected to OVER WIND and SETPOINT SUM
1:: SIGN 0 and SIGN 1 for changing directions in torque and speed modes. Other tension modes require configuration
changes to assure the speed demand changes correctly.
PID Enable
The PID needs to be enabled for the tension loop to operate. The enable input is at terminal C7, PID ENABLE. It can-
not be permanently connected to +24 volts or the integral will saturate and cause poor initial performance. Usually the
PID should be enabled when the drive is started, tension control is selected, and the section nip is closed.