LEFM 3xxCi User Manual
IB1406 Rev 12
Section 5
Page 34
August 2017
Figure 4.10 Ethernet Locations
Serial Communications – Recommended 16 to 28 AWG wire
The serial communications are Half-Duplex (two-wire). Terminations for serial communications are
provided in Table 4.. A typical schematic showing the serial communications is shown below in Figure 4..
Table 4.7 Terminations for Serial Communications
Port Name
Termination
User
COM1
TB2, Pin 1
Transmit/Receive (-)
1
TB2, Pin 2
Transmit/Receive (+)
1
COM2
TB2, Pin 17
Transmit/Receive (-)
2
TB2, Pin 18
Transmit/Receive (+)
2
COM3
(Not available with optional
HART)
TB2, Pin 19
Transmit/Receive (-)
1
TB2, Pin 20
Transmit/Receive (+)
1
MT-RJ Fiber
Connection
RJ45 Connection