Baker Hughes DigitalFlow XGF868i, Руководство по программированию

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1.9.3 Configuring the communications port
The XGF868i flowmeter is equipped with an RS232
serial interface. The meter can be configured with a
MODBUS option card for MODBUS communications, a
Foundation Fieldbus option card for Foundation Fieldbus
communications, an Ethernet option card for Ethernet
communications, or with a MODBUS/TCP option card for
MODBUS communication over the Ethernet, if desired.
NOTE: To set fieldbus communications parameters,
see Appendix E. Foundation fieldbus communications on
page 85 .
The serial port is used to transmit stored data and displayed
readings to a personal computer by connecting the meter’s
serial interface to the serial port of the PC. In addition, the
XGF868i can receive and execute remote commands, using
PanaView software via this link.
Use the COMM submenu to set the communications port
and MODBUS parameters. While programming the meter,
refer to Figure 30 on page 42 .
1.9.3a Setting up the Serial port
Use the steps below to configure the communications port:
1. In the
keypad program , scroll to prog and
press [enter].
2. In the prog menu, scroll to globl and
press [enter].
3. In the global program menu, scroll to comm
and press [enter].
4. Enter a meter address (between 1 and 127)
and press [enter]. (The default address is 1.)
A meter address is necessary for communication with
the Panametrics PanaView software. See Appendix
C, programming the XGF868i with PanaView™ , or the
PanaView™ user’s manual (910-211) for more information.
IMPORTANT
If the meter address or baud rate is changed,
communication with PanaView must be re-established
with the new parameters.
5. Scroll to the desired baud rate and press [enter].
(Available baud rates extend from 300 to 19200.)
6. If you have the standard RS232 serial interface, go to
procedure options .
1.9.3b Setting up MODBUS communications
When equipped with an optional MODBUS output card, the
XGF868i can transmit flow data serially to a flow computer,
or SCADA, using a Gould-type RTU protocol. Thus only the
MODBUS function command, 3 (read multiple registers),
6 (write multiple registers) is valid. The XGF868i uses the
following format for the data exchange:
• The
send command (initiated by the host flow
computer or controller) comes in the form: [time
delimiter]<addr><3><First register MSB>
<First register LSB> <register Count MSB>
<Register Count LSB><CRC low><CRC High>[time delimiter]
• The response (initiated by the host flow
computer or controller) comes in the form: [time
delimiter]<addr><3><Byte count><data. >
<CRC low><CRC High>[time delimiter]
The format for the returned data types is:
• Integer (16 bit Integer) <MSB><LSB> 1 register - 16 bit integer
• Integer (32 bit integerI) <MSB><LSB><LSB><LSB> 2 register -
32 bit integer
• Floating point (FP)<EXP><MAN><MAN><MAN> 2 registers -
32 bit IEEE floating point number
Use the steps below to configure MODBUS communications:
IMPORTANT
The XGF868i MODBUS communications settings chosen
in the next four steps must match those of the MODBUS
control system.
1. Scroll to the desired MODBUS baud rate and press [enter].
2. Scroll to the MODBUS parity and press [enter].
3. Scroll to the MODBUS stop bits and press [enter].
4. Enter a MODBUS meter address (between 1 and 254) and
press [enter]. (The default address is 1.)
IMPORTANT
You must reboot the XGF868i to load the new settings
Procedure options
After completing the above steps, the XGF868i returns to the
global program window. Do one of the following:
• Refer to the section Requesting parameters using MODBUS
on the following page to retrieve data from the XGF868i
using MODBUS.
• To continue regular programming, refer to Appendix A.
Menu Maps on page 39 , to navigate to the desired menu.
• To leave the keypad program , press [escape] three times.
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