Answer:
If the host is a PC, Hardware flow control is recommended.
However, in most control instrumentation, either software or no
flow control is called for.
2)
Question:
How do I disable any flow control?
Answer:
Simply disable both the Hardware and software control switch
settings. This is not recommended for large file transfers.
3)
Question:
I need to connect the Cellular Data Link to a machine which
does not understand your messages. All it needs is data. Which
configuration is recommended?
Answer:
Please use the ATQ1&w&w1<CR> command.
4)
Question:
Have you experienced that fact that communication with certain
brands of modems is unreliable?
Yes. And more so with generic brand which tend to throw hot
signals (i.e strong signal levels) on the line. This causes the
Cellular service to over-modulate which leads to distortions and
results in unreliable connections.
5)
Question:
What is the solution then?
Answer:
We recommend that you use modems that support MNP-10
and also allow transmit level to be reduced to between –15 dbm.
and –20 dbm. Rockwell based modem designs generally meet
these requirements.
For Rockwell based modems, please try the following commands
on the land line modem:
AT-SEC=1,18 <CR>. This will enable MNP 10 and set transmit
level to –18 dbm.
AT+MS=11,1,1200,4800&W&W1<CR>. Sets the modem to
communicate between 1200 and 4800 bps.
ATS91=15 <CR>.
6)
Question:
Is there any simple way to avoid frequent loss of connection?
Answer:
Please program the CDL 900 as follows
AT+MS=11,1,1200,1200&W&W1<CR>
This will force the CDL 900 to connect only at 1200 bps.
7)
Question:
Can IDC provide a landline modem I can use?
Answer:
Yes.
8)
Question:
What initialization string is recommended to communicate with a
non MNP modem?
9)
Answer:
Connection with non MNP landline modems is not recommended.
10)
Question:
My requirement(s) are totally unique. Can I count on IDC to help?
Answer:
Absolutely.
11)
Question:
Is there any recommended init string for various land line
modems?
Answer:
the following have been tried with great success:
a) For US Robotics / 3 Com modems:
ATS10=200&A3&B1&N2&U2&W&W1 <CR>
b) For Rockwell chip set based land-line modems 33600 and lower
AT%E2\N2S7=60S10=200+MS=11,1,1200,4800&w&w1 <CR>
c) For most other brands:
ATN0S37=6S10=200&w&w1 <CR>
