Moore Industries HIM, Руководство пользователя

Страница: 22 / 31

HIM
22 The Interface Solution Experts
Smart HART  Loop
Interface and Monitor
Configuring Analog Output Trimming
The Analog Output Trimming section of the software al-
lows you to match the HART monitors analog output to
the output measured by a calibration device. This will
require a calibrated multimeter, such as a HP Model
3478A or equivalent, accurate to ±0.009%.
Note:
Trimming the analog output of the monitor
nullifies any scaling that may have been
performed in the Scaling tab.
User Trimming
To trim the device, attach a multimeter to the analog
output, then click the
Fix Output at Low Point button.
Read the value on the multimeter, enter it into the
Measured Output Loop Current portion of the Trimming
box, and press Trim . Repeat this sequence until the
analog output matches the minimum point (4mA for a
4-20mA output) when you click the
Fix Output at Low
Point button.
After the low point is trimmed, press the Fix Output at
High Point button. Read the value on the multimeter,
enter it into the Measured Output Loop Current
portion of the Trimming box, and press Trim . Repeat
this sequence until the analog output matches the
maximum point (20mA for a 4-20mA output) when you
click the
Fix Output at High Point button .
When finished, press the Unfix Output button.
Figure 15.
Trimming Window
Fix Current Utility
The Fix Current Utility allows you to force the HIM to
output any current value from 0-20mA. This can be
used to match the calibration of your other equipment.
To fix the current, simply enter the value in the
Current
box (in mA) that you want the HIM to output, and click
Fix Output . When you are finished, make sure to press
the Unfix Output button so that the HIM can return to
normal operation.