PART THREE - OPERATION
SECTION 4 - CONFIGURING THE ANALYZER
Rev. 2-300
Accu4™ Low-range Turbidimeter System
41
4.3 Configuring Analog
Outputs (1 and 2)
☞
SET 0/4 and
20 mA VALUES
The analyzer provides two isolated analog outputs (1 and
2), each representing the measured turbidity. During cali-
bration, both analog outputs can be held at their present
values, transferred to a preset value, or remain active. Dur-
ing normal measurement operation, both outputs can be:
•
Held for up to 30 minutes by using the “CHECK CAL/
HOLD” function in the TEST/MAINT menu.
•
Held indefinitely by locally or remotely connecting both
TTL input terminals on TB1.
If a TEST/MAINT hold is applied in addition to a TTL hold,
both “holds” must be removed before the outputs return to
active status. If the outputs are set to “XFER” or “ACTIVE”
during a calibration, they remain in that state until after cali-
bration regardless of the TTL input status.
NOTE:
When using the HART communication option, a
digital signal is encoded onto the 4-20 mA analog
Output 1 signal. In a HART SINGLE MODE wiring
configuration, Output 1 remains available for normal
use. However, in a HART MULTI-DROP wiring con-
figuration, Output 1 becomes dedicated to that
function and cannot be used. See Part Three, Sec-
tion 8 for more HART communication information.
These instructions configure Output 1. Configure Out-
put 2 in the same way using its respective menu
screens.
You can set the turbidity values to define the endpoints at
which the minimum and maximum output values are desired.
1.
With the
top-level menu screen dis-
played and the “SET OUTPUT 1” line selected, press
ENTER key
to display
.
