Installation
4.3.4 Transmitter Operating Mode and Network Type
A transmitter outputs either an analog current or an equivalent digital signal, depending upon the selected
operating mode. The operating mode also determines the type of network (Point-to-Point or Multi-Drop)
to be installed, as shown in Table 4-1 and the following subsections.
OPERATING MODE
Analog
Digital
Note: If using a Model 375 Field Communicator, see the inside of the front
cover of this manual.
4.3.4.1 Analog Mode
When a transmitter is configured for analog mode operation, the following statements apply.
•
The transmitter outputs a 4-20 mA signal for input to devices such as controllers and recorders.
•
A Point-to-Point network is used comprising a transmitter, Primary/Secondary Master, and other non-
signaling devices. The transmitter polling address is 0 (zero).
Point-to-Point networks are shown in Figures 4-6, 4-7, and 4-8.
•
The optional display can be used for local indication of transmitter output.
•
Each transmitter is factory configured for analog mode unless otherwise ordered. The polling address
is set to zero (0).
•
A Model 275 HART Communicator is used for configuration, diagnostics, and reporting the current
process variable.
4-10
TABLE 4-1 Operating Mode and Network
NETWORK TYPE
Point-to-Point
Multi-Drop
UMSITRPDS3-1
NETWORK FIGURE(S)
4-6, 4-7, and 4-8
4-9
November 2005