ATO CMM 900-3W manual Frequently Asked Questions Faq, What is the flow control method recommended?

8. FREQUENTLY ASKED QUESTIONS (FAQ)

Q1:	What is the flow control method recommended?
A1:	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.
Q2:	How do I disable any flow control?
A2:	Simply disable both the Hardware and software control switch settings. This is
	not recommended for large file transfers.
Q3:	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?
A3:	Please use the ATQ1&w&w1<CR> command.
Q4:	Have you experienced unreliable communication with certain modems?
A4:	Yes. Several generic brands 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.
Q5:	What is the solution?
A5:	We recommend that you use modems that support MNP-10 and also allow
	transmit level to be reduced to between –15 dbm à –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 transmits level to –18 dbm.

∙AT+MS=11,1,1200,2400X3&W&W1<CR>. Sets the modem to communicate between 1200 and 2400 bps.

Q6:	Is there any simple way to avoid frequent loss of connection?
A6:	Please program the CMM 900-3W as follows
	AT+MS=11,1,1200,1200&W&W1<CR>
	This will force the CMM 900-3W to connect only at 1200 bps.
Q7:	What initialization string is recommended to communicate with non-MNP
	modems?
A7:	Connection with non-MNP landline modems is not recommended.
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