Hardware settings Proline t-mass 65
20 Endress+Hauser
4.2 Terminating resistors
!
Note!
If the measuring device is used at the end of a bus segment, termination is required.
This can be performed in the measuring device by setting the terminating resistors on the I/O
board. Generally, however, it is recommended to use an external bus terminator and not
perform termination at the measuring device itself.
Has to be set for measuring devices with the following communication methods:
• PROFIBUS DP
– Baudrate ≤ 1.5 MBaud → Termination can be performed at the measuring device, see
graphic
– Baudrate > 1.5 MBaud → An external bus terminator must be used
• MODBUS RS485 → Termination can be performed at the measuring device, see graphic
#
Warning!
Risk of electric shock! Risk of damaging the electronic components!
• All the safety instructions for the measuring device must be observed and all the warnings
heeded → ä 3.
• Use a workspace, working environment and tools purposely designed for electrostatically
sensitive devices.
A0007556
Setting the terminating switch SW1
on the I/O board:
ON - ON - ON - ON
1
2
3
4
W
E
N
O
1
2
3
4
W
E
N
O
1
2
3
4
W
E
N
O
1
2
3
4
W
E
N
O
1
2
3
4
W
E
N
O
1
2
3
4
W
E
N
O
1
2
3
4
W
E
N
O
390
+5V
3
4
1
2
OFF ON
220
390
SW1
W
W
W