User manual

41
© 2008, Elektro-Automatik GmbH & Co. KG
EN
Handling the device
8. The analogue interface
Introduction
The analogue interface is a 15pole Sub-D socket and is lo-
cated at the rear side. It is designed to remotely control the
most important functions of the electronic load by external
hardware (eg. SPS, switches, relays) with it.
The load requires to be switched to external control in
order to use the analogue interface. This is done by con-
necting Pin 7 (Remote) with ground (Pin 6) by a jumper
or switch. The status is then displayed like this:
Up to rmware 2.xx applies:
Avoid switching the load to external operation while running
it in remote mode (interface card) or battery test!
Since rmware 3.01 applies:
Switching to external control can be done in any situation
(except setup menu active). Eventually active remote control
or a running battery test are aborted and the control location
is set to „local“.
Priorities
The analogue interface has priority over any other operation
mode. Hereby the set value inputs are activated and the set
values for the load can only be adjusted from external by
means of an external voltage source (PLC, 0...10V applicati-
on) or potentiometers. See table „8.4 Pin assignment of ana-
logue interface“) for an overview of the inputs. Additionally,
the control via the interface card is blocked in this mode, but
actual values can be read with it (i.e. monitoring).
8.1 Correct use of the analogue interface
For details also see „8.3 Pin assignment of analogue inter-
face“.
The control of the electronic load via the analogue interface
requires to feed in at least the three set values for voltage,
current and power. Using internal resistance regulation
additionally requires a resistance set value RSEL, as well
as the selection of the resistance (R-RANGE) range to use.
Allowed level of all set value inputs is: 0...10V.
Caution! Use it at your own risk. The inputs are not pro-
tected against overvoltages. Higher voltage as specied
in 8.4 on any input of the analogue interface may damage
the device!
Please read and follow these instructions carefully:
• before connecting the hardware (with a Sub-D plug) which
is used to control the analogue interface, wire all necessary
connections and check the hardware for not supplying >10V
respectivelynotmorethanthespeciedvalue.
• the constant resistance regulation requires all four set va-
lues (U, I, P, R) to be fed in, if it‘s not used three set values
(U,IundP)aresufcient.
• if the constant resistance regulation is not used, it needs to
be deactivated by putting a jumper from Pin 12 (R-active)
to Pin 5 (AGND):
Pin 12 = 0V = Resistance regulation inactive
Pin 12 = open = Resistance regulation active
• if resistance regulation is used, you can select the resi-
stance range before or while using the analogue interface.
Pin 13 (R-Range) is used to switch between the two ran-
ges:
Pin 13 = 0V =Resistance range 2 is used
Pin 13 = 5V = Resistance range 1 is used (default)
• the input Rem-SB (Remote Standby, Pin 8) overlays the
pushbutton Input on/off(4). That means, that you can
switch the load input off or on with this pin at any time (even
if the load was not set to external control via the analogue
interface) and as long as this pin is tied to 0V (ground) the
load input will be permanently off and can not be set to on
with the pushbutton Input on/off(4) or via remote control
by an interface card.
• the output VREF can be used to generate set values for
the set value inputs VSEL, CSEL, PSEL and RSEL. For
example: in case that only CC regulation is required, the set
value input VSEL has to be tied to 0V, PSEL to VREF and
CSEL can either be fed from an external 0...10V source or
via a potentiometer (GND and VREF, slider to CSEL). See
also the table below.
• adjustable rise/fall times and pulse widths like in the
Level A/B mode are not effective here. If a certain form
of amplitude-time-progression is favoured, it has to be
generated by an external function generator and fed in.
• the trigger input (Trigger In) has no function when controlling
the load via analogue interface (External mode). That
means that set value leaps have to be generated with the
signal that is fed in to the set value inputs.
8.2 Examplecongurations
Hereyoucanndatablewithexamplecongurationsfor
various single or combined regulation modes. It always
applies, that Pin 7 (Remote) always has to be pulled to 0V
(DGnd) and Pin 12 (R-Active) only, if resistance regulation
is not used.
Explanation:itisnotnecessarilyrequiredtogiveaxed10V
to any non-variable input. It can of course also be a lower
voltage in order to limit, for example, the power. The table is
only a recommendation. Best to tie the non-variable inputs
to VREF respectively to GND, if required.
VSEL CSEL PSEL RSEL
only voltage regulation (CV) var. 10V 10V -
only current regulation (CC) 0V var. 10V -
only power regulation (CP) 0V 10V var. -
only resistance regulation (CR) 0V 10V 10V var.
current and power (CC+CP) 0V var. var. -
current and resistance (CC+CR) 0V var. 10V var.
The abbreviation„var.“ stands for a variable set value of 0...10V, which can
be, of course, pulsed in order to emulate the Level A/B operation.
Figure 15