Cooper Instruments & Systems DFI INFINITY Digital Force Indicator/Controller - Manual (Page 36)

transmission. Specifically, if command “^AE” is transmitted, it will cause the meter to switch to COMMAND
mode.
To be able to communicate with the meter when in Continuous Mode, do the following:
1. Transmit “X-OFF” character or make “RTS” line false.
2. Transmit “^AE” command. Now your meter is in Command Mode.
3. Do the communication with the meter.
4. Use “P1C” command to change BUS FORMAT (see Section 10.19 for Process, Strain Gauge, Temperature
and Universal meters and Section 11.25 for Rate meter/totalizer and batch meters) i.e., change bit #4 of “BUS
FT” from 1 to 0 to go back to Continuous Mode.
9.3 Multipoint Alarm Mode Response
The meter is commanded into the ALARM mode by detecting the alarm code-E03 for temperature, process,
strain, and universal meters, or E04 for rate/totalizer, batch meters-after its own address or the common 00
address. It stays silent unless an alarm already exists. If an alarm is detected, it immediately transmits its own
address with its alarm status characters. No turnaround time delay is used. All devices on the bus that are in
the ALARM mode drop out of that mode if any character is detected on the bus, so that bus contention is
minimized.
The program for the controlling device (computer) is usually written to poll the alarm status of all devices once
bus activity is detected after an alarm command, so that nearly simultaneous alarm conditions are properly
detected.
Such a meter poll by the computer after an alarm response usually starts at the detected device address, or at
device 01 in case of a garbled address (if two or more devices alarm at once).
If there is adequate time allowance in the data acquisition program, the computer may poll the alarm status of all
meters before commanding the ALARM mode to reduce the probability of bus contention and garbled
transmissions.
9.3.1 Meter’s Response Time
1) For Process, Strain Gauge, Temperature and Universal meters:
a) Slow mode = 0 to 300 ms
b) Fast mode = 0 to 100 ms
2) For Ratemeter/totalizer, Batch meter with chunk transmission:
a) Rate mode = 0 to 35 ms
b) Batch mode = 0 to 20 ms
c) Square-root mode = 0 to 40 ms
3) For Ratemeter/totalizer, Batch meter with one time transmission:
a) Rate mode = 0 to 80 ms
b) Batch mode = 0 to 50 ms
c) Square-root mode = 0 to 85 ms
NOTE: Although transmission’s program delay seems longer than chunk transmission, in most cases total
transmission time will be shorter, especially using 19200 baud rate.
9.4 External Print Command
CF 125 INFINITY SC GUIDE 32 M1519/N/0605
This command is valid in point-to-point and multipoint command mode only.