Purpose
To provide you with Modulation Selection (+MS) for your 28.8 or 33.6 PC Card. +MS allows you to select a modulation protocol. It allows you to enable and to disable Automode. You may also use +MS to choose your own, customized lowest and highest connection rates.
PC Card Jargon Guide
If any of the terms used in this Bulletin have you scratching your head then see Bulletin 3198, PC Card Jargon Guide.
Which PC Cards?
The information in this Bulletin is relevant to the following products.
- CC1288 and XJ1288
- CC4288 and XJ4288
- CC4336 and XJ4336
- SP1626
These PC Cards share a Rockwell v.34 chipset. We manufacture other 33.6 PC Cards that are based on other chipsets, ones that do not recognize the +MS Command outlined here. To determine the chipset and the initialization string information for all of our PC Cards, see Bulletin 3008.
This is an example of the format that your +MS command will follow. This example will set v.34 modulation fixed with a minimum of 2400 and a maximum of 33600. There are the five sections of the +MS command.
- AT+MS= is the way you begin the command so that your PC Card will read the settings that you would like.
- 11, Protocol is a one or two digit number that allows you to set the communications protocol.
- 0, Automode allows you to set modulation.
- 2400, Minimum rate at which you communicate.
- 33600 Maximum rate at which you communicate.
Here are the +MS commands that you will use to set the communications protocol through which you will connect. Notice that each protocol is appropriate for a certain range of speed though it does not actually set the speed of your connection.
- MS=0 for V.21 300bps
- MS=1 for V.22 1200bps
- MS=2 for V.22bis 2400bps
- MS=3 for V.23 1200bps send and 75bps receive
- MS=9 for V.32 4800 or 9600bps
- MS=10 for V.32bis 4800 to 14400
- MS=11 default for V.34 2400 to 33600
- MS=64 for Bell 103 300bps
- MS=69 for Bell 212 1200bps
- MS=74 for V.FC 14400 to 28800
V.FC is an unsupported protocol for our PC Cards. Our PC Cards are designed to PC Card standards. V.FC is not a PC Card standard. However, the PC Cards referred to in this Bulletin will accept the command.
There are two settings for modulation.
0 for fixed modulation.
1 for automode enabled. 1 is the default setting.
Set your minimum rate at an acceptable baseline rate of communications. In our example we have set to connect at 2400, the slowest speed allowed within the protocol.
Set the rate you desire within the range of speeds allowed under the protocol you have chosen. In our example, we have chosen 14400 which may be the highest acceptable speed under protocol 11 and with adverse line conditions.
For More
- To access the full command set available for the PC Cards discussed in this Bulletin, see the Rockwell V.34 AT Command Set Reference .
- How To Contact Customer Support .
- Links To Other Resources On The World Wide Web.
If you need a response from one of our Applications Engineers then please E-Mail Customer Support.
