User manual

Page 33
EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
PSI 5000 A Series
3.5.4 Remote control via the analog interface (AI)
3.5.4.1 General
The built-in, up to 1500 V DC galvanically separated, 15-pole analog interface (short: AI) is on the rear side of the
device offers the following possibilities:
• Remote control of current, voltage and power
• Remote status monitoring (CC/CP, CV)
• Remote alarm monitoring (OT, OVP)
• Remote monitoring of actual values
• Remote on/off 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 not 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 cannot 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 ex-
ternal voltage or generated by the reference voltage on pin 3. As soon as remote control via the analog interface
is activated, the values displayed will be those provided by the interface.
The AI operates in the common voltage range 0...10 V or 0...5 V for 0...100% of any nominal value. The reference
voltage is, by default, set to 10 V, but can be switched to 5 V by command via digital interface. The setting is per-
manently stored. For details refer to the external guide “Programming ModBus & SCPI”.
Notes for use of the interface.
• 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 is not used for adjust-
ment,itcanbetiedtoadenedlevelorconnectedtopinVREF(solderbridgeordifferent),soitgives100%
The analog interface is galvanically separated from DC output. Therefore do not con-
nect any ground of the analog interface to the DC- or DC+ output!
3.5.4.2 Acknowledging device alarms
Device alarms (see 3.6.2) are always indicated in the front display and some of them are also reported as signal on
the analog interface socket (see 3.5.4.3), for example the overvoltage alarm (OV), which is considered as critical.
In case of a device alarm occurring during remote control via analog interface, the DC output will be switched off
the same way as in manual control. While alarms OT and OV can be monitored via the corresponding pins of the
interface, other alarms like power fail (PF) can’t. Those could only be monitored and detected via the actual values
of voltage and current being all zero contrary to the set values.
All device alarms (OT, OV, PF, OCP and OPP) have to be acknowledged, either by the user of the device or by the
controlling unit. Also see „3.6.2. Device alarm handling“. Acknowledgement is done with pin REM-SB switching
the DC output off and on again, means a HIGH-LOW-HIGH edge (min. 50ms for LOW).
Alarm OT, as signalled on pin 6, can only be acquired while the overtemperature condition is
present. It means, after the device has cooled down, the alarm automatically deletes. It can
only be acquired later on by reading the alarm counter via digital interface.