User manual

Page 40
EL 9000 T Series
www.elektroautomatik.de
[e-mail]
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
3.5.4 Remote control via the analog interface (AI)
3.5.4.1 General
The optionally available, galvanically isolated, 15-pole analog interface (short: AI, also see section 1.9.9) is located
on the back side of the device after installation and offers the following possibilities:
• Remote control of current, voltage, power and resistance
• Remote status monitoring (CC/CP, CV)
• Remote alarm monitoring (OT, OVP, PF)
• Remote monitoring of actual values
• Remote on/off switching of the DC input
Setting the three set values of voltage, current and power via the analog interface must always be done concur-
rently. 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 internal resistance set value can additionally be adjusted.
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 will be in control. Analog set values can be supplied by an external
voltage or generated from the reference voltage on pin 3. As soon as remote control via the analog interface is
activated, the display set values will be those provided by the interface.
The AI can be operated in the common voltage ranges 0...5 V and 0...10 V, both representing 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gura-
tion via MENU“ for details. The reference voltage sent out from pin 3 (VREF) will be adapted accordingly:
0-5 V: Reference voltage = 5 V, 0...5 V set value signal for VSEL, CSEL, PSEL and RSEL correspond to 0...100%
nominal value, 0...100% actual values correspond to 0...5 V at the actual value outputs CMON and VMON.
0-10 V: Reference voltage = 10 V, 0...10 V set value signal for VSEL, CSEL, PSEL and RSEL correspond to 0...100%
nominal values, 0...100% actual values correspond to 0...10 V at the actual value outputs CMON and VMON.
Input of excess signals (e.g. >5 V in selected 5 V range or >10 V in the 10 V range) are clipped by the device by
setting the corresponding set value to 100%.
Before you begin, please read these important notes for use of the interface:
• Analogremotecontrolofthedevicemustbeactivatedbyswitchingpin“REMOTE”(5)rst.Onlyexceptionis
pin REM-SB, which can be used independently
• 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 inputs, such as VSEL, CSEL, PSEL and RSEL (if R mode is activated), must not be left unconnected
(i.e.oating)duringanalogremotecontrol.Incaseanyofthesetvaluesisnotusedforadjustment,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 isolated from DC input. Therefore do not connect any
groundoftheanaloginterfacetotheDC-orDC+input!
3.5.4.2 Resolution and sample rate
The analog interface is internally sampled and processed by a digital microcontroller. This causes a limited resolu-
tion of analog steps. The resolution is the same for set values (VSEL etc.) and actual values (VMON/CMON) and
is 26214 when working with the 10 V range. In the 5 V range this resolution halves. 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.