Fluid Components International GF03 - Manual (Page 35)

Doc. No. 06EN003352 Rev. B 3 1 Model GF03 Flow Meter
FLUID COMPONENTS INTERNATIONAL LLC http://www.fluidcomponents.com
The flowmeter has one RS-232 port. The data stream is sent at a rate of 9600 baud with no
parity, 8 bit characters and 1 stop bit. The baud rate is fixed and cannot be changed. All
operations accessible through the keypad are also available through the serial port. The serial
port, designated as JP3, is located on the lower right corner of the upper circuit board. The
connection is a RJ-11 phone jack. Figure 24 represents the connection between the serial port
and the host device.
A serial communications kit containing adapter plugs are available from FCI for both the DB-
9 and DB-25 connectors which allow the use of standard 6 wire phone line cord between the
RJ-11 serial port and the host device. The order number for the DB-9 Connector kit is 014108-
01. Serial communication software is provided with each connector.
NOTE: The standard phone line used must be a reversing type and not a straight-through
type of cable.
The serial port input/output stream duplicates the actions of the keypad and the LCD display.
Commands sent through the serial port to manipulate the flowmeter are exactly equivalent to
the keypad sequences. Data coming out of the serial port is equivalent to the data sent to the
display. Remote communication with the flowmeter consists of character sequences that
duplicate actions taken at the keypad. For example, the string H 2 4 2 5 produces the same
results as pressing HOME, 2, 4, 2, 5 from the keypad. Figure 25 is an example of code written
in Quick Basic that extracts the flow rate and the temperature through the serial port.
A common communication problem is over writing flowmeter serial buffer. If the buffer is
overwritten the last characters sent are lost. If the flowmeter does not respond as expected
to a command, slow down the data flow from the user PC or control device.
Serial
Communications
6
5
4
3
2
1
GF Series Serial Port
RJ-11 Phone Jack
1
2
3
4
5
6
RJ-11 Pin
Description
DCD
DTR
TXD
RXD
GND
IBM PC
DB-9 Connector
Data Carrier Detect
Data Termial Ready
Transmit Data
Receive Data
Ground
+5V
NC
DTR
TXD
RXD
GND
1
2
3
4
5
6
RJ-11 Pin
Description
DCD
DTR
TXD
RXD
GND
IBM PC
DB-25 Connector
Data Carrier Detect
Data Termial Ready
Transmit Data
Receive Data
Ground
+5V
NC
DTR
TXD
RXD
GND
20
8
3
2
7
1
4
3
2
5
C00251-1
Figure 24 - Wiring Diagram, DB-9 an DB-25 PC Connectors