16
8.13 4mA Adjustment
If the 4-20 mA setting is turned ON (8.1
Setting the 4-20
mA Output)
, the following two menus will appear. The first
menu outputs a constant 4 mA while allowing for a small
amount of adjustment. The adjustment can be made using
the
and
buttons. This adjustment will allow the operator to make
the CLX-Ex2 agree with a PLC or SCADA system. The adjustment
limits are ± 200 counts or about ± 0.2 mA.
This setting will be slightly different on each instrument as each
CLX-Ex2 will be factory set to 4.00mA. Press the
button when
adjustments are complete to save this setting and move on to the
20mA adjustment.
8.14 20mA Adjustment
This menu operates similar to the previous menu. This menu outputs a
constant 20 mA while allowing for a small amount of adjustment. The
adjustment can be made using the
and
buttons. The adjustment
limits are ± 1000 counts or about ± 1 mA.
This setting will be slightly different on each instrument as each CLX-Ex2
will be factory set to 20.00mA.
When complete with the 20mA adjustment, press the
button to exit
to AUTO mode and save all configuration settings.
9.0 Additional Features and
Options
9.1 RS-485 Outputs
The CLX-Ex2 has the capability to operate in two different RS-485
modes. Included are a simple communication mode and Modbus
communications. Both modes will automatically configure and do not
require any changes or selections.
9.1.1 Simple Communication
The CLX-Ex2 can provide basic communications over simple programs
such as the Hilgraeve HyperTerminal that is included with most
Microsoft Windows packages. The user could also use Visual Basic
or other programs. The factory setting communication
parameters are 8 bits, no parity and 1 stop bit. These can
be changed in the Extended CONFIG menus 8.9
RS-485
Parameters.
The master computer will send out:
• Byte #1 the attention character “
:
” in ASCII or
3A
Hex
• Byte #2 the address of the CLX-Ex2 being queried
• Byte #3 & 4 CR LF or 0D 0A in hex
The CLX-Ex2 will respond with:
• The same attention character “
:
” in ASCII or
3A
Hex
• The address of the CLX-Ex2
• The Reading
• The Unit (mg/L)
A sample communication would look like this:
(Master computer requesting a report
from address #1)
:1 CRLF
(CLX-Ex2 set to address #1 Response)
:001 0.0249mg/L
9.1.2 Modbus Communication
Modbus protocol communication is included with this instrument.
The Modbus address list is available from HF scientific or online at
www.hfscientiifc.com.
