User manual

B-4
Appendix B MC-III™ EXP Flow Analyzer
Express Connect Option
By default, the MC-III interface software automatically attempts to connect to the instrument when a user
clicks on the desktop application icon. This feature is controlled by the “Always attempt Express Connect on
program startup” checkbox setting in the Communications Option screen (Figure B.4, page B-3).
When multiple devices are daisy-chained together in a network, the “express connect” function can interfere
with the user’s ability to connect to a specic device. To disable the Express Connect function, deselect the
“Always attempt...” checkbox and click “OK.”
The software will now attempt to connect with the instrument
only when the user clicks on the LCD image on the Welcome screen or selects File>Express Connect. For
more information, see Software Connection in Multi-Device Network, page 49.
To cancel the “express connect” function without disabling the autorun option, the user can toggle between
connect/disconnect by clicking in the LCD area of the device on the Welcome screen.
Auto-Negotiate Option
When connected devices are capable of switching baud rates automatically or when devices are directly
connected to an MC-III EXP, a user may congure the MC-III interface to automatically negotiate the fastest
baud rate during device connection. This “negotiated” baud rate does not replace the congured baud rate,
but rather provides a temporary boost of baud rate while the computer is connected to the device for faster
downloads. After the software disconnects, the device reverts to the congured baud rate.
By default, this function is disabled. To enable automatic baud rate negotiation on device connect, check the
“Attempt auto-negotiation….” check box in the Communications Option screen (Figure B.4, page B-3) and click
“OK”. To initiate an immediate search for the fastest baud rate without exiting to the Welcome screen, check
the “Enable auto-negotiated baud rate” checkbox, click the “Test Now” button to the right of the checkbox,
and click “Yes” at the prompt in the Conrm dialog box.
Enable Auto-Negotiated Baud Rate Option
The “Enable auto-negotiated…” checkbox enables usage of the baud rate that has been automatically selected
or “negotiated” by the MC-III interface, either upon connection with the instrument or when the “Test Now”
button was last clicked. See also Auto-Negotiate Option above.
Toggle RTS Line Option
Some RS-485 to RS-232 converter modules require a request-to-send (RTS) line for switching between a
“receive” and “transmit” state. This checkbox allows the software to toggle this line, ensuring that incoming
data will be readily transmitted and that the converter will not stall in a “receive” mode after a period of
inactivity (see Figure B.4, page B-3). By default, this option is enabled. To disable the option, deselect the
checkbox and click “OK.”
Enable Modbus Address Support for Firmware Versions 1.06 through 1.08
Operators with MC-III units programmed with rmware versions 1.06 through 1.08 must check the checkbox
labeled “Enable Modbus Address Support for Firmware Versions 1.06 through 1.08” to ensure seamless
Modbus communication with their units. Operators using any other rmware version with the MC-III should
leave the checkbox unchecked.
Timing Parameters
Presend Delay
On the Communications Options screen (Figure B.4, page B-3), a user can enter a presend delay (milliseconds)
to help ensure a successful connection between the computer and the MC-III EXP when the instrument is
networked with a radio or other low-speed device. The computer transmits a request to send, which turns