Yokogawa HART Communicator YHC5150X - Manual (Page 36)

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When connecting the communicator
to a loop with a resistive load greater than 250 Ωs, the HART ®
jacks
may be connected across the load, the loop + and -, or to the HART
®
device communication terminals. Refer
to the following diagram for connecting across the loop + and -.
.
Do not connect the communicator across the loop supply. This does not provide the
proper resistance and no HART
®
communication will be possible.
4.3 HART
®
Communication
Upon power up the communicator automatically polls for HART ® devices in the range specified on the
HART
®
Setup System menu (default range is zero).
The HART
® Connection status bar on the system screens indicates the current state of the HART ®
connection.
If you select the gray bar, no action will occur. The communicator will continue to send poll address
messages within the configured range as long as a device has not been selected for connection. If new
devices are added to the loop, within the configured range, they will be detected automatically.
Or the currently selected device is in the process of connecting.
When the bar is gray: there is no device connected;