Instructions

Page 57
EA Elektro-Automatik GmbH
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Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
PS 9000 3U Series
3.5.4 Remote control via the analog interface (AI)
3.5.4.1 General
The built-in, galvanically isolated, 15-pole analog interface (short: AI) is on the rear side of the device o󰀨ers the
following possibilities:
• Remote control of current, voltage and power
• Remote status monitoring (CV, DC output)
• Remote alarm monitoring (OT, OVP, PF, OCP, OPP)
• Remote monitoring of actual values
• Remote on/o󰀨 switching of the DC output
Setting the three set values via the analog interface always takes place concurrently. It means, that for example
the voltage can’t be given via the AI and current and power set by the rotary knobs, or vice versa.
The OVP set value and other supervision (events) and alarm thresholds can’t be set via the AI and therefore must
be adapted to the given situation before the AI is put in operation. Analog set values can be fed in by an external
voltage or generated by the reference voltage on pin 3. As soon as remote control via the analog interface is ac-
tivated, the values displayed will be those provided by the interface.
The AI can be operated in the common voltage ranges 0...5 V and 0...10 V in each case 0...100% of the nominal
value. The selection of the voltage range can be done in the device setup. See section „3.4.3. Conguration in the
setup menu“ for details.
The reference voltage sent out from Pin 3 (VREF) will be adapted accordingly and is then:
0-5 V: Reference voltage = 5 V, 0...5 V set values (VSEL, CSEL, PSEL) correspond to 0...100% nominal values,
0...100% actual values correspond to 0...5 V at the actual value outputs (CMON, VMON).
0-10 V: Reference voltage = 10 V, 0...10 V set values (VSEL, CSEL, PSEL) correspond to 0...100% nominal values,
0...100% actual values correspond to 0...10 V at the actual value outputs (CMON, VMON).
Input of excess set values (e.g. >5 V in selected 5 V range or >10 V in the 10 V range) are clipped by setting the
set value at 100%.
Before you begin, please read these important notes about the use of the interface:
After powering the device and during the start phase the AI signals undened statuses on the
output pins such as ALARMS1. Those must be ignored until is ready to work.
• Analog remote control of the device must be activated by switching pin REMOTE (5) rst
• Before the hardware is connected that will control the analog interface, it shall be checked that it can’t provide
voltage to the pins higher than specied
• Set value input, such as VSEL, CSEL and PSEL, must not be left unconnected (i.e. oating)
• It is always required to provide all three set values at once. In case any of the set values isn’t used for adjustment,
it can be tied to a dened level or connected to pin VREF (solder bridge or di󰀨erent), so it gives 100%
3.5.4.2 Resolution and sample rate
The analog interface is internally sampled and processed by a digital microcontroller. This causes a limited res-
olution of analog steps. The resolution is the same for set values (VSEL etc.) and actual values (VMON/CMON)
and is 26214. Due to tolerances, the truly achievable resolution can be slightly lower.
There is furthermore a max. sample rate of 500 Hz. It means, the device can acquire analog set values and states
on digital pins 500 times per second.