DESCRIPTION AND OPERATION
SMART TRANSMITTER COMMUNICATION
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I-E96-304A
®
transmitter parameters such as range, or to calibrate transmit-
ter output. Transmitters also send process and status data
through the ASI for the Infi 90 system to monitor. Access this
status data from the status reports. Refer to
for more
detail on using the status reports.
MFP Communication
The MFP communicates with the ASI over the slave expander
bus in parallel digital format. The ASI slave bus interface con-
verts this parallel format to serial digital format and sends it to
the transmitters over the current loop.
STT Terminal Communication
An adapter jack on the front plate of the ASI allows the connec-
tion of a portable Smart Transmitter Terminal (STT). The STT
monitors outputs of a field device connected to the ASI. It han-
dles these transmitter commands: select the channel, change
the ID tag, report the input or output, report the status, get the
configuration data.
Smart Transmitter Communication
System start-up downloads the smart transmitter configura-
tions and operating ranges from the MFP through the ASI. The
MFP sends commands to the transmitters to change parame-
ters. Command functions include: calculating range, doing
output calibration, and operating an automatic remote mani-
fold.
Command Buffering During Transmitter Communication Failure
If any command fails to get to a transmitter, the ASI halts com-
munication with that transmitter. The ASI already has the
transmitter setup data stored in memory. The ASI now stores
the set of transmitter commands an operator enters during the
communication failure. The ASI can store two commands, one
from each column in the list.
The ASI tries to restart communication with a failed smart
transmitter once each minute. When communication over a
failed channel resumes, the ASI downloads the setup data and
stored commands to that transmitter.
AUTOZERO
MANIFOLD RUN
OUTPUT ZERO
MANIFOLD ZERO
OUTPUT SPAN
FIX OUTPUT
CANCEL