Detcon 700 HRT Bridge - Manual (Page 18)

HRT Bridge
700 Sensor HRT Bridge IM Rev.0.2 Page 14 of 18
9) When both the 4mA and the 20mA have been calibrated the procedure will return the HRT Bridge to
automatic control.
Loop Test
1) Ensure that the DVM is connected as prescribed in Figure 8:
a) Disconnect the wire from the HART Connectors mA/HART position.
b) Connect one end of a 100~250Ohm resistor to the mA/HART position of the HART Connector.
c) Connect the positive lead of a DVM set to measure milliamps to the other end of the resistor.
d) Connect the negative lead (-) of the DVM to the GND position of the connector. (Figure 8)
2) Select “Loop test” from the Loop test Calibrate section of the screen.
3) The procedure will prompt for a setting (“4mA”, “20mA”, “Other”, and “End”).
4) Select one of the settings or “End” to exit.
5) If “Other” is selected, the procedure will prompt for a value. Only valid values will be accepted.
6) Select “OK”.
7) The HRT Bridge will set the output for selected milliamp value.
8) Compare the reading on the DVM to the output displayed. Select “OK” when ready to continue
9) The procedure will return to Step 3. If “End” is selected, the HRT Bridge will exit Loop test and return to
automatic control.
4.3.3 HART Setup
The HART Setup Screen allows parameters of the HRT Bridge to be changed or modified. Changes made on
this screen will not be applied until power is cycled on the unit.
Figure 9 HART Setup
• Tag – Text that is associated with the field device installation. This text can be used by the user in any
way. A recommended use is a unique label that correlates to a field device label: a plant drawing, or on
a control system. This variable is also used as a type of data link layer address handle.
• Long Tag – Functions exactly like the Tag except the size is larger (max 32 ISO Latin 1 characters).
• Descriptor – Text that is associated with the field device. This text can be used by the user in any way.
There is no specific recommended use.