Connecting the md-21 in a 20ma current loop – Westermo MD-21 User Manual

Page 6

Advertising
background image

RD

TD

TD

RD

Connecting the MD-21 in a 20mA current loop

12

6151-2002

3

4

3

4

RD

1

2

1

2

3

4

1

2

TD

TD

TD

Master

S1: 3 on
S3: 1, 2 on
S4: 3–6 on

S1: 3 on
S3: 1, 2 on
S4: 1, 2 on

Slaves

RD

RD

3

4

3

4

1

2

1

2

3

4

1

2

TD

Master

S1: 3 on
S3: 3–6 on
S4: 3–6 on

S1: 3 on
S3: 1, 2 on
S4: 1, 2 on

Slaves

RD

Functional description

When transmitting from the master, RD and TD flash. RD flashes on both slaves.
When transmitting from a slave both RD and TD flash and on the other slaves and
the master RD flashes.

Functional description

When transmitting from a slave the TD led flashes only on that unit. The RD led flashes
only on the master modem.

When transmitting from the master, TD flash. RD flashes on both slaves.

Half duplex transmission

Full duplex transmission

Advertising