Hach sc1000 - Manual (Page 128)

126
Troubleshooting
8.5 Test the expansion cards in the Maintenance menu
8.5.1 Test the output card
In the TEST/MAINT menu, every output current can be set to certain values for testing
reasons. If necessary, each output can be adjusted as well. Additionally, the current state
of the outputs can be requested.
The output current can be set to certain values and then be adjusted with an offset and a
factor.
To set these two parameters:
1. Set the SET OFFSET value to “0” and the SET FACTOR value to “1”.
2. Set the output current (CURRENT OUT) to “4 mA” and then only adjust the SET
OFFSET value until the output current is really 4 mA.
3. Set the output current (CURRENT OUT) value to “20 mA”, then adjust the factor until
the output current is really 20 mA and cross-check the 4 mA.
4. Repeat the steps 1-3 until the output precision reaches a desired value.
TEST/MAINT
OUTPUT SETUP
mA OUTPUT INT/EXT
FUNCTION TEST
OUTPUT 1-4
CURRENT OUT Select an output current and set at the appropriate output.
SET FACTOR
Default value: 1
Adjusts the output current with an factor changed with this value.
SET OFFSET
Default value: 0
Adjusts the output current with an offset changed with this value.
ALL
Default: 0 mA
Sets OUTPUT 1-4 to 0, 4, 10, 12 or 20 mA.
SET OUTMODE
Default value: HOLD
Decides how other members react if they try to read an output current value while the output
current card is in the function test. As the value of the output current in the function test is not
based on any calculations, other members reading this value probably have to be informed
about this special situation.
HOLD
Another reading member does not use the current read value, but uses the last value before the
output current card was in the function test mode.
ACTIVE
Another reading member uses the current value even when the output current card is in the
function test mode.
SET TRANSFER The reading member uses an own substitute value for its own output value.
STATUS OUTPUT
Indicates the status for each output current channel and probe which is read from the output
current card.
SENSOR OK
The according output channel is working fine and the current output card is able to read the data
from the probe to set the output current.
SENSOR MISSING
The according output current channel cannot get data from the probe because the probe is not
responding anymore. In this case the output current has the value set in SYSTEM SETUP>SET
TRANSFER or holds the according current value read the last time the probe was responding.
SENSOR FAIL
The output current card communicates with the according probe, but this probe has got an
internal failure and cannot provide reliable data. In this case the output current has the value set
in the menu SET TRANSFER in SYSTEM SETUP or holds the according current value read the
last time the probe was responding.