Eurotherm Drives 590 DRV Digital, Product Manual

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Appendix D I/O Configuration - System Menu
590 DRV Digital DC Drive Product Manual App. D - 5
D
Analog Inputs - Examples
Inputs can be connected to any writable parameter. The read/write status of each parameter is listed in the right-
hand column in Appendices G, H, and I. RO is read only and RW is read/write.
Controlling the accel time of the drive ramp through analog input 1
In this example, an operator wishes to control the acceleration time of the drive speed ramp over a 0 to 30 second
range with an external potentiometer. The ends of the pot are connected to the drive's 0 to +10 VDC supply (terminals
A1 and B3) and the wiper of the pot to terminal A2. Because the range of both the acceleration and deceleration times
are scaled as 0 to 100.00% = 600.0 secs, the signal needs to scaled to give 30 seconds at 100.00%, or when the
potentiometer is turned up to +10 VDC. Otherwise, the pot will have a large, unresponsive deadband range and a
small but highly sensitive adjustment range at its low end making accurate setting difficult.
30 seconds = CALIBRATION , CALIBRATION = 5.00%
600.0 seconds 100.00%
1. Set CONFIGURE I/O::CONFIGURE ENABLE to ENABLE.
2. Find the tag numbers for the RAMP ACCEL TIME using the table in Appendix I (tag number 2).
3. Set ANIN 1 (A2)::DESTINATION TAG to 2 (RAMP ACCEL TIME).
4. Set ANIN 1 (A2)::CALIBRATION to 0.0500 (5.00%).
5. Set MAX CLAMP to 100.00%. (Default)
6. Set MIN CLAMP to 0.00%.%.
7. Reset CONFIGURE I/O::CONFIGURE ENABLE to DISABLE.
Analog input 1 (terminal A2) now controls the speed ramp acceleration rate over a range of 0 to 30 seconds. An input
of 10 volts yields a 30 second acceleration time. The deceleration rate of the speed ramp remains fixed at its default
setting of 10 seconds.
NOTE. If you wish to control both the accel and decel time from a single external source, you must
configure the Analog Input 1 block output to two destinations using an internal link. Refer to the
INTERNAL LINKS section appearing later in this chapter.
Figure D.3 - Controlling the Ramp Accel Time Using an External Potentiometer Wired to an Analog Input