Emerson Rosemount 702 Quick Start Manual page 21

August 2018
Figure 33: Fuel Sensor Cable Wiring
A. TT-MLC-MC-BLK (Leader Cable)
B. TT5000/TT5001 Sensor cable (up to 500 ft.)
C. TT-MET-MC (End termination)
D. TT-MJC-xx-MC-BLK (Optional jumper cable)
E. TT-ZBC-xx-MC-BLK (Branch connector)
F. TT-MET-MC (End termination)
G. TT-MET-MC (End termination)
H. Up to 500-ft. TT5000 or TT5001 sensor cable (Total per 702)
Important notes regarding the use of Tyco TraceTek Fast Fuel Sensor and TraceTek sensing cable:
■ Tyco TraceTek sensors must be installed as per manufacturer recommendations.
■ Do not run the Rosemount 702 Transmitter for long periods (more than two weeks) with a Tyco fuel sensor in the leak state as
this will more rapidly deplete the power module.
Liquid hydrocarbon detection interface, for Modbus
Table 5 on page 21 describes use of the Rosemount 702 Transmitter for hydrocarbon detection in other communications
protocols such as Modbus or OPC. It is imperative that both PV and SV be mapped to the host system so as to make a good
interpretation of the condition and status of the leak detector.
Table 5: Liquid Hydrocarbon Detection Interface, for Modbus Mapping
PV
1.0
0.0
1.0
NOTICE
It is imperative that both PV and SV be mapped to the host system so the diagnostic information on the sensor status is captured.
In addition, system considerations must be observed to ensure that the device is still connected to the wireless network and
reporting values. On an Emerson Smart Wireless Gateway, this can be done by referring to the parameter: PV_HEALTHY.
PV_HEALTHY has a "True" state when the device is on the network and its updates are current, not late or stale, and the device is
functioning properly. A "False" state of PV_HEALTHY means the device is either off the network, the data updates are not current,
or that there is a malfunction of the device (such as an electronics failure). In the case of a "False" state of PV_HEALTHY, it is
recommended to assume the device is not connected to the network and take appropriate action.
Quick Start Guide
®
mapping
SV
1.0
1.0 or 0.0
0.0
Description/interpretation
Normal condition, no leak detected,
sensor status good
Leak detected, sensor status good
Sensor Not Connected, Assume Leak,
take appropriate action
21