Instruction Manual
MX7M Active Gauge
3 RS-485 and USB Communications
This gauge communicates with the host computer through an RS-485 or USB interface. Each commu-
nication correspondence consists of a command line sent by the host computer and a response from
the gauge.
To communicate with the MX7M via RS-485, the user must have an RS-485 capable device to send
commands to the MX7M . Each command must be preceded by a *, the address, and will be an S, R,
W, RC, or WC.
To communicate with the MX7M via USB, the user must have a USB capable device to send commands
to the MX7M . Each command must be preceded by a * and will be an S, R, W, RC, or WC. Because USB
is a serial bus, the unit address is omitted from commands. See the Communications Specifications
heading for information on what settings are necessary to properly communicate with the MX7M .
3.1 Changing Communications Settings
The communication parameters, (baud rate, address, etc.), are changed through the local menu.
Please see the section in this manual entitled Explanation of Menu Items and Navigation for more
information on navigating and editing within the menu. Below are provided some specifics on the
RS-485 and USB Communications of the MX7M .
3.2 Communications Specifications
Table 4: RS-485 Communication Specifications
Interface
RS-485 compatible
Data Transfer Method
Synchronous/half duplicate method
Baud Rate
9600/19200/38400/57600/115200
Data Format
1 start bit, 8 data bits, 0 parity bits, 1 stop bit
Error Detection
Parity bit
Parity Bit
None
Stop Bit
1
Transfer Distance
Max 100 meters
Table 5: USB Communication Specifications
Interface
USB type B receptacle on module
Type
USB 2.0
Class
USB communications device class (USB CDC)
Baud Rate
115200
Transfer Distance
Max 5 meters
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