Pin Assignment X3 Ser1 Tty / 20 Ma Current Loop - Omron NT4S Operation Manual

The Terminals of the NT-Series
1.5.2

Pin Assignment X3 SER1 TTY / 20 mA Current Loop

TTY / 20 mA current loop, passive
Pin Designation
10 T+
13 R+
14 R-
19 T-
TTY / 20 mA current loop, active
Pin Designation
10 T+
12 S1+
13 R+
14 R-
16 S2+
19 T-
21 S1-
24 S2-
Termination:
When using the channel SER1 as current loop the terminator switches for RS485
must be switched OFF!
The interface can be connected as either an active or passive current loop depend-
ing on the wiring. The transmit line and the receive line are provided with separate
20mA power sources. The compliance voltage is approximately 24 VDC.
The maximum baud rate is 19200Bd. The maximum cable length depends on the
baud rate and rate of transmission errors.
For longer cable lengths, the 20mA power supply should be fed by the transmitting
unit. This can decrease crosstalk on the signal lines considerably.
In idle state (signal logical 1) a current loop of 20 mA can be measured on the cable.
Signal logical 1 - Current flow 20mA
Signal logical 0 - Current flow is interrupted
A shielded cable with twisted pair wires (cable type LiYCY-TP) and a minimum
cross section of 0.08 mm
Connect the cable shield to the metal hoods of the connectors over as large a
surface as possible!
Channel Function
SER1 Transmit Data, Positive Polarity
SER1 Receive Data, Positive Polarity
SER1 Receive Data, Negative Polarity
SER1 Transmit Data, Negative Polarity
Channel Function
SER1 Transmit Data, Positive Polarity
SER1 Power Source 2, Positive Polarity
SER1 Receive Data, Positive Polarity
SER1 Receive Data, Negative Polarity
SER1 Power Source 1, Positive Polarity
SER1 Transmit Data, Negative Polarity
SER1 Power Sink 1, Negative Polarity
SER1 Power Sink 2, Negative Polarity
2 must be used. The maximum cable length is 100 m.
Section 1-5
33