Deif PPU - Connection with 3-wire Shielded Cable

PPM Installation Instructions
DEIF A/S Page 59 of 69
Connection with 3-wire shielded cable:
This solution is only feasible if the COM line is insulated. Check
PLC/other device before connecting.
Non-insulated COM line may result in damage to the equipment.
Connect shield to ground at one end only. Shield ends must be insulated
with tape or insulation tubing.
Use shielded twisted cable.
Normally, the Modbus does not need bias resistors (end terminators). These
are only needed in case of very long lines and/or many nodes (>32) on the
Modbus network. If bias resistors are needed, the calculation should be
based on the following data:
- A line internal pull-up bias resistor: 22 k
- B line internal pull-down bias resistor: 22 k
- Receiver input sensitivity: +/-200 mV
- Receiver input impedance: 12 k
Cable: Belden 3105A or equivalent. 22 AWG (0.6 mm
2
) twisted pair, shielded,
<40 m/m, min. 95% shield coverage.
PLC or other device
DATA -
(
B
)
COM DATA +
(
A
)
Not used
DATA -
(
B
)
COM
DATA +
(
A
)
Multi-line
29 30 31 32 33 34 35 36
Not used Not used
DATA +
(
A
)
DATA -
(
B
)
Not used
DATA -
(
B
)
COM
DATA +
(
A
)
Multi-line
29 30 31 32 33 34 35 36
Not used Not used
DATA +
(
A
)
DATA -
(
B
)
Not used
DATA -
(
B
)
COM
DATA +
(
A
)
Multi-line
29 30 31 32 33 34 35 36
Not used Not used
DATA +
(
A
)
DATA -
(
B
)