From Technologic Systems Manuals (sandbox)
Product Page
TS-MULTI_104 Schematic
Multitech Universal Socket Products
MTSMC-H5 (HSPA) Product Support
MTSMC-G2 (GPRS) Product Support
Operating Temperature
Cold -40C
Hot 85C
Some modems have smaller operating temperatures
96mm X 89mm
Weight 20.4 (approx)

1 Overview

The TS-MULTI-104 is a PC/104 device that carries Multitech socket modems. It uses a standard 16550 driver, and is designed to work with nearly all PC/104 hosts.

2 Getting Started

The TS-MULTI-104 will use the standard 16550 driver provided by the host system, but the driver will need to know the COM address and IRQ which are both selected by the onboard jumpers.

This example is for a TS-7800 with only IRQ6 and the 1.8MHz jumpers on.

# If you are in Debian the next 2 lines will turn on the PC104 bus
. /initrd/ts7800.subr
modprobe ts7800_isa16550 irq=6 io=0x3F8

To view if it loaded correctly, run 'dmesg' and you should find a line similar to this:

serial8250: ttyS2 at MMIO 0xee0003f8 (irq = 70) is a 16550A

So in this case the COM device will be /dev/ttyS2. You can use a terminal emulator like minicom or picocom to quickly test communication. Upon typing "AT" and pressing enter, the modem should respond with OK.

2.1 Getting a Data Connection

Using our Linux boards you would use pppd to dial up to your carrier. For example, these scripts will work with tmobile:



connect "/usr/sbin/chat -v -f /etc/ppp/chatscripts/tmobile"
disconnect "/usr/sbin/chat -v -f /etc/ppp/chatscripts/tmobile-disconnect"



"" "\p\p\p\p\p\p\p\p\p\p\p\p+++\p\p\p\p\p\p\p\p\p\p\p\p"
"" "ATH0"

"OK" 'AT+CGDCONT=1,"IP","wap.voicestream.com"'

OK 'ATD*99***1#'


"" "\K"
"" "+++ATH0"

Using a different carrier you will likely only need to replace wap.voicestream.com with the access point for your carrier.

To start pppd:

pppd call tmobile

# Or for more logging information:
# pppd nodetach call tmobile

This will create a ppp0 interface that can now be used as a standard network interface, and should set up a default route to the internet.

2.2 Frequency Selection

The default configuration for the MTSMC-G2 module is for 1900MHz/850MHz which is used in the US, but this is configurable through software. You can find a list of gsm frequencies used by various countries here. If you require 900MHz/1800MHz you can add in the line before the AT+CGDCONT line in your chat script:

"" 'AT+WMBS=5,1'

You can replace the 5 with any from this table:

Band Frequency
0 850MHz
1 900MHz extended (900E)
2 1800MHz
3 1900MHz
4 850MHz/1900MHz
5 900E / 1800MHz
6 900E / 1900MHz

The second argument of 1 tells the modem to restart immediately on the requested frequencies.

2.3 Faster Data Rates

While the MTSMC-G2 (GPRS) is limited to 115200 baud, the MTSMC-H5 (HDSPA) can communicate over serial up to 921600 allowing actual transfer rates around 80-90KB/s.

When used with the GPRS modems and those requiring a maximum baud rate of 115200, you can use the PC104 clock to generate a 1.84MHz clock needed for the 16550. When using faster modems like the H4 for an HSDPA connection you can remove the 1.8MHz jumper to use the alternative 14.7456MHz crystal. This will allow you to reach baud rates up to 921600. This will require you to specify a custom baud_base to the serial driver.

To set a custom baudrate in Linux you would typically use the setserial command. When the spd_cust baud rate it set Linux will re-purpose 38400 to use your custom baud rate.

Common Baud Rates
Divisor Rate
1 921600
2 460800
3 307200
4 230400
5 184320
6 153600
7 131657
8 115200

Larger divisors will also work, but this should cover the common range. Using the setserial command you can specify the divisor. For example, to reach 115200 with the alternative baud base:

# ttyS2 is an example, but check "dmesg" after loading
# your 16550 driver to get the device
setserial /dev/ttyS2 spd_cust baud_base 921600 divisor 8

Next you will need to tell the modem to communicate at the faster baud rates. You can use a client like picocom or minicom to connect directly to the modem to send it commands.

picocom -b 38400 /dev/ttyS2

Even though we are talking at 115200, 38400 must be specified since we are using a custom baud_base. You can test communication with the modem again by typing "AT", pressing enter, and receiving "OK". To reconfigure the modem to the faster 921600 baud rate you can send it this command:


This will respond with OK, but now you will need to quit out of picocom (ctrl a,x) and reconfigure the baud base to use divisor 1:

setserial /dev/ttyS2 spd_cust baud_base 921600 divisor 1

The only change now needed is in your providers file. From the example tmobile configuration you would need to edit /etc/ppp/peers/tmobile and change 115200 to 38400. Starting pppd will now allow communication around 80-90KB/s (depending on your local cell tower's availability).

3 Features

3.1 COM Port Address

COM I/O COM1 Jumper COM2 Jumper COM3 Jumper

3.2 PLD

The TS-MULTI-104 board contains a PLD with 1 register. This is available at offset 0x140, or if R10 is depopulated 0x160. Bit 1 will allow you to put the modem in reset. For example, on a TS-7800:

# On the 7800 PC/104 8 bit devices are at 0xEE000000
peekpoke 8 0xEE000140 1

This will hold the modem in reset. To bring the modem back up:

peekpoke 8 0xEE000140 0

3.3 IRQ Selection

The IRQ can be selected by the jumpers labelled IRQ3 through IRQ7. On most of our SBCs only IRQ5-7 are used.

4 Product Notes

4.1 FCC Advisory

This equipment generates, uses, and can radiate radio frequency energy and if not installed and used properly (that is, in strict accordance with the manufacturer's instructions), may cause interference to radio and television reception. It has been type tested and found to comply with the limits for a Class A digital device in accordance with the specifications in Part 15 of FCC Rules, which are designed to provide reasonable protection against such interference when operated in a commercial environment. Operation of this equipment in a residential area is likely to cause interference, in which case the owner will be required to correct the interference at his own expense.

If this equipment does cause interference, which can be determined by turning the unit on and off, the user is encouraged to try the following measures to correct the interference:

Reorient the receiving antenna. Relocate the unit with respect to the receiver. Plug the unit into a different outlet so that the unit and receiver are on different branch circuits. Ensure that mounting screws and connector attachment screws are tightly secured. Ensure that good quality, shielded, and grounded cables are used for all data communications. If necessary, the user should consult the dealer or an experienced radio/television technician for additional suggestions. The following booklets prepared by the Federal Communications Commission (FCC) may also prove helpful:

How to Identify and Resolve Radio-TV Interference Problems (Stock No. 004-000-000345-4) Interface Handbook (Stock No. 004-000-004505-7) These booklets may be purchased from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.

4.2 Limited Warranty

Technologic Systems warrants this product to be free of defects in material and workmanship for a period of one year from date of purchase. During this warranty period Technologic Systems will repair or replace the defective unit in accordance with the following process:

A copy of the original invoice must be included when returning the defective unit to Technologic Systems, Inc. This limited warranty does not cover damages resulting from lightning or other power surges, misuse, abuse, abnormal conditions of operation, or attempts to alter or modify the function of the product.

This warranty is limited to the repair or replacement of the defective unit. In no event shall Technologic Systems be liable or responsible for any loss or damages, including but not limited to any lost profits, incidental or consequential damages, loss of business, or anticipatory profits arising from the use or inability to use this product.

Repairs made after the expiration of the warranty period are subject to a repair charge and the cost of return shipping. Please, contact Technologic Systems to arrange for any repair service and to obtain repair charge information.

4.3 RF Exposure

To comply with FCC RF safety exposure limits, the antenna used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be located or operating in conjunction with any other antenna or transmitter.

4.4 Multitech

4.4.1 FCC Notes

The antenna gain, including cable loss, for the device you are incorporating into your product design must not exceed the requirements at 850 MHz and 1900 MHz as specified by the FCC grant for mobile operations and fixed mounted operations as defined in FCC CFR Title 47 Part 2.1091 and FCC CFR Title 47 Part 1.1307 of the FCC rules for satisfying RF exposure compliance. Power output listed is conducted. This device is a mobile device with respect to RF exposure compliance. The antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20cm from all persons and must not be co-located or operated in conjunction with any antenna or transmitter except in accordance with FCC multi-transmitter product guidelines. Installers and end users must be provided with specific information required to satisfy RF exposure compliance for installations and final host devices. (See note under Grant Limitations.) Compliance of this device in all final host configurations is the responsibility of the Grantee.

4.4.2 Grant Limitations

This device has been granted modular approval for mobile applications. Portable applications may require further RF exposure (SAR) evaluations. Examples of mobile devices include wireless routers, desktop computers, utility meters, etc. Examples of portable applications include devices such as a laptop, USB dongle, mobile phone, tablet PC, and any device that can be worn on the body during use.