ATI Model F12/D Gas Transmitter Part 4 – Operation
67
O&M Manual (Rev-H)
COM Setup Menu
The COM Setup Menu is used to select the protocol and configure the transmitter’s connection settings.
Figure 90. COM Setup Menu
HART
The following applies to transmitters that have the HART FSK modem interface and HART FSK firmware
option.
A HART “point-to-point” connection permits simultaneous digital and analog communication between one or two
masters and one slave device. A HART multi-drop connection permits one or two masters and up to 15 devices to
communicate digitally, but prohibits analog communication by requiring each slave device to fix its output at its lowest
level (4mA). For more information, see the HART Transmitter connection examples in
Figure 27 on page 28, or consult the HART Foundation (www.hartcomm.org) for details on how to
connect a HART transmitter.
HART FSK devices communicate digitally by imposing a 1mA pk-pk waveform on the 4-20mA output
using a technique called Frequency-Shift-Keying. FSK interprets binary 0 as one cycle at 2200 Hz, and
binary 1 as one cycle at 1200 Hz. Since each cycle increases the output by ½ mA and then decreases it
by ½ mA, it FSK does not affect the average analog level. This allows a HART FSK device to use both
analog and digital communication on a single connection.
Change the slave protocol.
ASCII (default)
Modbus (option)
HART (option)
None
Protocol selection is performed at the factory and may not be
changed. Settings for the ASCII and Modbus protocols may be
changed, but are restricted for the HART protocol.
Change the physical communication interface that the
transmitter will control during transmit and receive functions:
RS232 (available for ASCII or Modbus, not for HART)
RS485 (available for ASCII or Modbus, not for HART)
FSK (HART only)
Change the baud rate of the transmitter’s UART.
May be set to: 300, 600,1200, 2400, 4800, 9600, 14.4k, 19.2k,
28.8k, 38.4k, 57.6k, 115.2k, 230.4k, and 460.8k.
The value is fixed at 1200 for HART FSK, and defaults to 9600 for
Modbus and ASCII.
Change the parity, number of data bits, and number of stop bits
of the transmitter’s UART:
N,8,1 …no parity, 8 data bits, 1 stop bits
N,8,2 …no parity, 8 data bits, 2 stop bits
E,8,1 …even parity, 8 data bits, 1 stop bit
O,8,1 …odd parity, 8 data bits, 1 stop bit
The value is fixed at O,8,1 for HART protocol, and defaults to
N,8,1 for Modbus and ASCII.
Interface=FSK
Baud Rate=1200
Settings= O,8,1
…COM>Setup
Interface=RS485
Baud Rate=9600
To Next Page
Loading...