Manual switching amplifier BS 805
Page 8 of 12
Subject to technical change 10/2017
A.S.T. Angewandte SYSTEM-TECHNIK GmbH Dresden
7.3. Signal settings
With the aid of an ammeter and/or LED corresponding to Section 4, the zero point is set by means of the >0<
adjuster, the load value for sensor loading being set using the >V< adjuster.
Setting the zero point with the >0< adjuster
- De-charge the sensor.
- The zero point 4mA is correctly set at the very point where the red LED just about lights up
.
- Output current below 4mA: Turn >0< adjuster clockwise,
- Red LED remains on: Extend zeroing range in minus
direction applying functions 452 or 451
- Output current exceeds 4mA: Turn >0< adjuster counter-
clockwise,
- Green LED remains on: Extend zeroing range in plus
direction applying functions 453 or 454
Setting the load value using the >V< adjuster
- Charge the sensor.
- The load value, e.g. 20mA is correctly at the point where the red LED does not yet light up.
- Output current below 20mA: Turn >0< adjuster
clockwise,
- Red LED remains off: Extend zeroing range with
functions 44x
- Output current exceeds 20mA: Turn >V< adjuster
counter-clockwise,
- Red LED remains on: Extend zeroing range with
functions 43x
Whenever the appliance detects an error (refer to point 4 LED display, LED U78) an output current of 2mA is always
generated and the red LED >U1< lights up.
A note can be made of the test signal (Code No.: Switch-on 422, Switch-off 423) for documentation purposes later on.
For this purpose de-charge the sensor, measure the output signal and connect the test signal by means of function
422. Now measure the output signal and switch the test signal back off again by means of function 423. A note is
made of the difference between the output signals which can then be reviewed when checks are carried out at a later
point.
Setting the switching points >SP1< and >SP2<
Setting of the switching points with the aid of the rotary potentiometers SP1 and SP2 governing the relays takes place
applying the corresponding test loads or, if proceeding from a computed current signal, by means of the constant-
current settings (Code No. 311 to 355).
The switching action of the relays needs to be set as required using key >T1< (Code No. 211 to 255).
After being connected, the sensor is charged with a test load. If the test load cannot be attained or no constant setting
is possible, an alternative in lieu of this is to set a constant current applying the functions 31x
