D–4
Using the D2–DCM with Modems
Data Communications Module, 2nd Edition, 2/03
Set the D2–DCM Switches
For the most part, we suggest that you follow the setup instructions shown earlier in this
manual. That is, choose the protocol you’re using, set the station address, etc. However,
there are a couple of important differences which are discussed here.
It is important that you select the following communications parameters when you use the
D2–DCM for remote communications.
D
9600 baud
D
NO parity
The parity setting is most important. Most popular modems cannot transmit an odd number
of bits per character. If parity is enabled, each character would consist of 1 start bit, 8 data
bits, 1 parity bit and 1 stop bit, making a total of 11 bits per character. Since this is an odd
number, the modem would not work properly. You can experiment with the baud rate settings,
but make sure all components are set to the same baud rate.
If you’re using a radio modem, you may have to set a delay time for the communications. This
time is necessary to allow time for the radio to “key-up” before the data is transmitted. You
must match the settings required by your modem.
Delay Time
Baud
1
2
3
300
ON
OFF OFF
600
OFF
ON
OFF
1200
ON
ON
OFF
2400
OFF OFF
ON
4800
ON
OFF
ON
9600
OFF
ON
ON
19200
ON
ON
ON
38400 OFF OFF OFF
Baud Rate
Switch Positions
NO Parity
Set to OFF
Time*
6
7
8
0
OFF OFF OFF
2
ON
OFF OFF
5
OFF
ON
OFF
10
ON
ON
OFF
20
OFF OFF
ON
50
ON
OFF
ON
100
OFF
ON
ON
500
ON
ON
ON
*Delay time in milliseconds
Switch Positions
OFF ON
SW5
1
2
3
4
5
6
7
8
(9600 shown)
(see modem
manual)
Baud Rate & Parity
Delay Time
ON
Содержание D2-DCM
Страница 4: ...D2 DCM Data Communications Module Manual Number D2 DCM M...
Страница 37: ...1A Cable Diagrams...
Страница 47: ...Data Communications Module 2nd Edition 2 03 B RLL Communications Programs...
Страница 58: ...Data Communications Module 2nd Edition 2 03 C Using the D2 DCM with MODBUS...
Страница 67: ...Data Communications Module 2nd Edition 2 03 D Using the D2 DCM with Modems...
