18
Serial Communication
Serial Communication
Connecting your device to a computer allows you to log the data that it generates. The
device communicates digitally through its communications connector and cable using a real
or virtual COM port on your computer. This section of the manual shows you how to operate
the flow meter using ASCII commands.
Modbus RTU Communication
For details on Modbus commands, please visit
alicat.com/manuals
for the Modbus operating
bulletin.
Establishing Communication
After connecting your device using a communications cable, you will need to establish serial
communications through a real or virtual COM port on your computer or programmable logic
computer (PLC).
•
For a serial port connection, note its COM port number, which can be found in the
Windows® Device Manager program.
•
Most computers will recognize your USB as a virtual COM port. If it does not, download
the appropriate USB device driver at
alicat.com/drivers
and note the COM port number
as found in Windows® Device Manager.
The meter will be configured with the following settings:
• Baud:
19200 (by default; others can be used if the computer, computer software, and
the meter are all set to the same rate)
• Data bits:
8
• Parity:
none
• Stop bits:
1
• Flow control:
none
Alicat’s Serial Terminal Application
Alicat’s Serial Terminal is a preconfigured program for serial communications that functions
much like the older Windows® HyperTerminal, with plain text in a command-line format.
Download Serial Terminal for free at
alicat.com/drivers
. Once downloaded, simply run
SerialTerminal.exe. Enter the COM port number to which your device is connected and the
baud rate of the flow meter. The default baud rate is 19200, but this is adjustable by entering
the
RS-232 Serial
menu
on your flow meter (
✓
Note:
In the following examples,
indicates an ASCII carriage return (decimal 13,
hexadecimal D). For many devices, this is the same as pressing the Enter key. Serial
commands are not case-sensitive.
Polling Mode
Polling mode and a unit ID of
A
is default, unless otherwise requested. Polling the device
returns a single line of data for each request. To poll your device, simply enter its unit ID.
Poll the device:
[unit ID]
Example:
a
(polls unit A)
You can change the unit ID of a polling device by typing:
Change the unit ID:
[current unit ID]
@=
[desired unit ID]
Example:
a@=b
(changes unit A to unit B)
The unit ID can be changed via the device’s front panel (
). Valid unit IDs are letters
A–Z, and up to 26 devices may be connected, as long as each unit ID is unique.
