Digi m10
Technical Overview
And
Reference
Date: 12 January 2012
90033936_C
Copyright Notice
Digi International has prepared this manual for the use of its employees, agents, and its
customers. This manual c ontains proprietary information, which is prote ct ed by copyright.
Preparing derivative works or providing inst ruction based on this manual without written
permission from Digi International is prohibit ed.
All information in this manual is accurate and reliable to the best of Digi Internati onal's
knowledge. Digi International may make improvement s and / or changes in this manual at any
time without prior notice.
Trademarks
The Digi m10 is a registered trademark of Digi Internat ional Inc. All other company and / or
product names mentioned in this manual are t he property of their respective owners.
Document Revision History
Version Description Date
1.00 Initial release of the user manual 23 Sep 2008
1.10 FAQ section added and minor changes made 30 Sep 2008
1.20 Technical review changes and minor additi ons 21 Oct 2008
1.30 Extract hardware information into sep arate manual 20 Aug 2009
Rev A Complete revision 12 Nov 2009
Rev B Table 3 in section 4.2 revised to display correct format 4 Nov 2010
Rev C Updated section 4.6 12 Jan 2012
Digi m10 Technical Overview
Digi International, Inc. © 2009
iv
Table of Contents
About This Manual......................................................................................................................... 6
Target Audience .......................................................................................................................... 6
Symbols Used in This Manual ..................................................................................................... 6
Reference Documents ................................................................................................................. 7
Where to Get Help ....................................................................................................................... 7
1. General Description ............................................................................................................... 8
1.1 Background .................................................................................................................... 8
1.2 Communication using a Digi m10 Satellite Modem ....................................................... 9
2. Types of Communication Methods .................................................................................... 11
2.1 Data Reports ................................................................................................................ 11
2.2 Messages ..................................................................................................................... 11
2.3 Global Grams ............................................................................................................... 11
3. Terms and definitions: ........................................................................................................ 12
3.1 Gateway ....................................................................................................................... 12
3.2 Gateway Earth Station (GES) ...................................................................................... 13
3.3 Subscriber Communicator (SC) ................................................................................... 13
3.4 SC Terminated ............................................................................................................. 13
3.5 SC Originated ............................................................................................................... 13
3.6 Global Gram ................................................................................................................. 13
3.7 Message Blocking ........................................................................................................ 14
3.8 Message Priority ........................................................................................................... 14
3.9 Speed Dial .................................................................................................................... 15
3.10 Message Acknowledgments ........................................................................................ 15
3.11 Alternate Terminating Address (ATA) / Message Forwarding ..................................... 16
3.12 Delivery Plan ................................................................................................................ 16
3.13 GES-to-Satellite Channels ........................................................................................... 17
3.14 GES-to-GCC Channels ................................................................................................ 17
4. Digi Extended Packets ........................................................................................................ 18
4.1 Temperature Out of Bounds Packet ............................................................................. 18
4.2 Temperature Query ...................................................................................................... 19
4.3 Temperature Query Response ..................................................................................... 20
4.4 NVM Data Corruption Alert Packet .............................................................................. 21
4.5 Code Upgrade Packet .................................................................................................. 21
4.6 RTS/CTS Control Packet ............................................................................................. 23
Appendix A: Upgrade Firmware ................................................................................................. 25
Digi m10 Technical Overview
Digi International, Inc. © 2009
v
List of Tables
Table 1: Message Acknowlegements ............................................................................................ 16
Table 2: Temperature Out of Bounds Packet ................................................................................ 18
Table 3: Temperature Query Packet ............................................................................................. 19
Table 4: Temperature Query Response Packet ............................................................................ 20
Table 5: NVM Data Corruption Alert Packet .................................................................................. 21
Table 6: Code Upgrade Packet ..................................................................................................... 21
Table 7: RTS/CTS Control Packet ................................................................................................. 23
List of Figures
Figure 2: SCO Report Transmission Cycle ..................................................................................... 9
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 6 of 26
About This Manual
This manual provides a detailed technical overvi ew on how the Orbcomm satellite network
operates, available message types, specific Digi mess age extensions, and other related technical
information.
Target Audience
The target audience for this document is co mprised engineers and other individuals with a
technical background. A typical reader is an engineer who is familiar with the general concept of
wireless data communications.
Symbols Used in This Manual
Symbol Description
Provides additional information corresponding to the current topic.
Warning! If ignored, may cause permanent dam age to the JumpStart Kit or injury to
a person.
Caution! Failure to comply with a caution may res ul t in failure or damage to the
device.
Danger! Failure to comply with a danger symbol m ay result in serious injury.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 7 of 26
Reference Documents
The following documents were used to create this user guide, and provide more information
about the technologies and standards involved using the Digi m10 ORBCOMM Satellite Modem.
Department of Defense Test Method Standard for Environmental Engineering Considerations
and Laboratory Tests, MIL STD 810E
European Telecommunications Standards Institute, EN 300 832 (A1 version 1.1.1),
Electromagnetic Compatibility for Mobile E arth Stations.
International Electrotechnical Commissi on, IEC 1000-4-4, Testing and Measurement
Techniques -- Immunity to Fast Transient / Burst Immunity Test.
International Electrotechnical Commissi on, IEC 61000-4-6, Testing and Measurement
Techniques -- Immunity to Conducted Dist urbances, Induced by Radio-Frequency Fields.
ORBCOMM Serial Interface Specification, E80050015.
ORBCOMM Subscriber Communicator (SC) Standards and Specifications, E25050102.
ORBCOMM Subscriber Communicator Type A pproval Plan, A25TP0017.
ORBCOMM System Overview, A80TD0008.
RoHS FAQ -- http://www.rohs.gov.uk/FAQs.aspx#10
Society of Automotive Engineers, SAE J1455, Joint S AE / TMC Recommended
Environmental Practices for Electronic Equipment Design (Heavy-Duty Trucks).
Technical Requirements for Satellite Earth S tations and Systems (SES); Mobile Earth
Stations (MES) Providing Low Bit Rate Data Communications (LBRDC) using Low Earth
Orbiting (LEO) satellites operating below 1 G Hz, E N 3200 721.
Where to Get Help
For additional information or clarifications regarding this user manual, please get in touch with
Digi International using the contact info rmation provided below.
Address
Phone
E-mail
11001 Bren Road East
Minnetonka, MN 55343
952-912-3456
http://www.digi.com/support/eservice/login.jsp
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 8 of 26
1. General Description
This chapter provides an overview of the Digi m10 Satellite Modem and its features.
1.1 Background
The ORBCOMM system is a two-way system that supports communication to and from mobi le or
fixed satellite modems, also called
message or other data is first generated by an S C. From that source, the message is transmitt ed
to the nearest ORBCOMM satellite. The satel li te downlinks the message to the
Station (GES), which then transmits the message to the desired Gateway Control Center (GCC).
Within the GCC, the message is processed and f orwarded to its ultimate destination by the
Gateway Message Switching System (GMSS). T he destination may be another satellite modem,
a pager, a corporate resource management sy st em or any personal or business e-mail or Internet
address.
The ORBCOMM system is available to transfer information for an end user whenever a satellite is
in view of the SC. If the satellite is connected to a GES, the satellite is considered in real-time
messaging mode, and the message is passed immediately through to the GCC for routing to its
final destination. If the satellite is not connected to a GES, the satellite switches to a store-andforward mode to accept
200 bytes) stored on-board the satellite unt i l it connects to the SC’s host GCC through an
affiliated GES.
Global Grams. Global Grams are short messag es (up to approximately
Subscriber Communicators (SCs). In most applications, a
Gateway Earth
For detailed information on the ORBCOMM sy st em , refer to the ORBCOMM System Overview
document that was provided as part of your Digi JumpStart Kit..
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 9 of 26
1.2 Communication using a Digi m10 Satellite
Modem
Once an antenna is properly hooked up to the Digi m1 0 and i t has a clear line of sight to the sky,
the Digi m10 can start communicating with satelli tes as they move overhead. Availability of
satellites is highly dependent on regional location and how b usy a satellite currently is; that is, the
availability of slots.
Figure 1: SCO Report Transmission Cycle
To transmit a message through the Digi m10 to the satellite, a user must create a message and
communicate it serially to the Digi m10. See the section referring to the types of
Communication methods or the available types of messages that can be sent. At this time,
various
queued up for transmission and there is a satellite overhead, the Digi m10 will attempt to transmit
the message to the satellite following the cycle shown in the above figure. When the satellite
accepts the message and transmits to the GES, the message then routes to the specified
destination.
acknowledgement and priority levels can be set as well. Once a message has been
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 10 of 26
When receiving a message through the Digi m10, a user creates a message using an SMTP
client and sends it to the ORBCOMM GCC using t he appropriate e-mail address (typically
serial#X1@orbcomm.net for North America or serial#X1@orbcomm2.net for the rest of the
world). When the message is received by the GCC, the GCC transmits it through the GES to the
satellite in orbit, which then transmits the message down t o the Digi m10. Once the message is
received by the Digi m10, the user can query for the message serially. Note the Data Available
signal asserts when the Digi m10 has received a message.
The message packets sent between the Digi m10 Satellite Modem and the Satellite are optimi zed
at 107 bytes of user data. This allows for a single packet to be sent to the Satellite with a single
acknowledgement back. After that, the nex t optimized size is 228 bytes of user data, and then in
111 byte increments.
Alternatively, users can provision their Digi m10 Satellite Modems for IP Gateway usage. This
usage allows customers to use HTTP POST and GET commands with XML to send and receive
messages against a specified host server. When the Digi m10 Satellite Modem is set up for an
IP Gateway account, speed dial 1 is used to route messages to the host server.
Note: If the Digi m10 is powered off, all existing messages in its transmit and receive
queues are lost.
Digi m10 Technical Overview v 1.20
Digi International, Inc. © 2009
Page 11 of 26
2. Types of Communication Methods
2.1 Data Reports
A Data Report is the basic service element the Digi m10 uses to transmit or receive a single
packet containing 6 bytes or less of user-defined data. A Data Report can require an
acknowledgment of successful delivery to t he O RBCOMM Gateway, but this acknowledgment
can be omitted to save space segment resour ces. A Data Report can only use speed dials to
indicate where the message should be delivered.
More documentation can be found on the CD provided wit h the JumpStart Kit. To learn
more, please refer to corresponding secti ons in the ORBCOMM Serial Interface Specification
document.
2.2 Messages
A Message is the basic service element the Digi m 10 uses to transmit or receive a longer
sequence of data. To ensure reliability, messages are transferred over the satellite rese rv ation
channels via short packets containing a checksum, with all packets acknowledged or
retransmitted. Messages must fit within a 1024-by te packet. Messages can either use a speed
dial to indicate the message delivery destination or an e-mail address.
2.3 Global Grams
A GlobalGram is the basic service element the Digi m10 uses to transmit or receive a single, selfcontained data packet to or from a satellite t hat is not currently in view of an
ORBCOMM Gateway. This allows remote and oc eanic areas to be served in a “store-and-
forward” mode. For an SC-Terminated Global Gram, the relaying satellite stores the dat a packet in
memory and transmits it upon request from the dest i nation Digi m10. An SC-Terminated
GlobalGram contains 182 bytes of user data. For an SC-Originated GlobalGram, the satellite
receives the GlobalGram from the Digi m10, ac knowledges it and archives it in satellite memory
until the destination ORBCOMM Gateway est abl ishes contact with the satellite. An SC-Originated
GlobalGram contains 229 bytes of user data. A Global Gram can only use speed dials to indicate
where the message should be delivered.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 12 of 26
3. Terms and definitions:
3.1 Gateway
An ORBCOMM Gateway consists of a Gateway Control Center (GCC) and one or more Gateway
Earth Station (GES) sites, as well as the network components that provide interfacility
communications. The principal role of the ORBCOMM Gateway is to provide message pro cessing
and subscriber management for a defined service area. This role includes serving as the “home”
for ORBCOMM system subscribers, as well as provi ding the interface between the subscriber
and the interconnected public and private data networks and the Public Switched Telephone
Network (PSTN)
The current ORBCOMM Gateways consist of the Western Hemisphere (Gateway ID of 1), the
Eastern Hemisphere (Gateway ID of 120), and Japan (Gateway ID of 130).
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 13 of 26
3.2 Gateway Earth Station (GES)
The role of the Gateway Earth Station (GES ) i s t o provide an RF communications link between
the message switch and the satellite constellation. It consists of medium gain tracking antennas,
RF and modem equipment, and communications ha rdware and software for sending and
receiving data packets. The GES equipment and site are designed for unattended operation. The
GES uses radome-enclosed, VHF full-motion ant ennas with approximately 17 dB of gain. Two
fully independent antenna systems, and associated RF and control equipment, provide complete
functional redundancy at a GES site.
3.3 Subscriber Communicator (SC)
The term Subscriber Communicator (SC) refers in general to the satellite modem or a device
incorporating a satellite modem.
3.4 SC Terminated
Messages sent to the SC from the GES
More documentation can be found on the kit instal lation CD. To learn more, navigate to
C:\Program Files\Digi\Digi m10 JumpStart Kit\documents please refer to either ORBCOMM Serial
Interface Specification > SC-TERMINATED MESSAGE or ORBCOMM Serial Interface
Specification > Figure 4.8 SC-Terminated Message.
3.5 SC Originated
Messages sent from the SC to the GES
More documentation can be found on the kit install ation CD. To learn more, navigate to
C:\Program Files\Digi\Digi m10 JumpStart Kit\documents please refer to either ORBCOMM Serial
Interface Specification > SC-ORIGINATED MESSAGE or ORBCOMM Serial Interface
Specification > SC-ORIGINATED MESSAGE.
3.6 Global Gram
Global Gram messaging, or store-and-forward message transfer, is available in instances when a
satellite is in view of a satellite modem, also referred to as Subscriber Communicator (SC), but
there are no ORBCOMM gateways connected to the satellite. Examples of such instances
include ocean areas and locations where there is no gateway, but regulatory approval for a
satellite modem to communicate with a satellit e has been granted. Global Grams allow satelli tes
and satellite modems to archive short messages when the destination ORBCOMM gateway is
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 14 of 26
inaccessible by the satellite constellation. The stored messages are transmitted when an
ORBCOMM Gateway comes into satellite-transmission range. This concept applies to both
sending (SC-Originated) and receiving (SC-Terminated) fro m a satellite modem point of view.
More documentation can be found on the kit instal lation CD. To learn more, navigate to
C:\Program Files\Digi\Digi m10 JumpStart Kit\documents please refer to either ORBCOMM Serial
Interface Specification > Figure 4.5 SC-Originated Globalgram & Figure 4.6 SC-Terminated
Globalgram or ORBCOMM Serial Interface S pecification > SC-ORIGINATED GLOBALGRAM &
SC-TERMINATED GLOBAL.
3.7 Message Blocking
Message Blocking is an optional feature that allows customers to restrict the addresses to which
their satellite modems can send messages, and those addresses that are allowed to send to a
satellite modem. The Speed Dial addresses are used as permitted addresses.
3.8 Message Priority
Message priority is a feature that allows mes sages to be processed in order of importance. The
higher the priority, the faster the message m oves through the network. However, the ORB COMM
message switch (OMS) does not terminate message sessions in progress; a new urgent
message will remain queued until any active lower-priority message is co m pl eted.
ORBCOMM will only implement priority restrictions during periods of very heavy usage. If the
system is lightly loaded and no queues, or only very short queues, are formed, there is little user
benefit gained from the priority feature.
Functionally, within the ORBCOMM gateway congestion control mechanisms use priority to stop
satellite modems from sending messages not m eeting a customer-designated priority threshol d.
The satellite broadcasts the identification number of connected gateways and their minimum
message priority thresholds in the downl ink control information. All listening satellite m odems that
have messages queued for a listed gateway m ust refrain from sending messages below the
specified priority threshold. Only queued messages with a priority at or above the minimum
priority threshold are sent. Messages below the m ini mum priority remain in the queue until
channel utilization falls below the threshold.
The available priority levels are:
0. Non-urgent
1. Normal
2. Urgent
3. Special Delivery
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 15 of 26
3.9 Speed Dial
The ORBCOMM gateway maintains a list of up to eight speed dials, or originator/recipient
addresses for each satellite modem. Typically, these speed dials contain the e-mail addresse s of
frequent recipients or originators of mes sages to and from the satellite modem. The us e of speed
dials results in a reduced number of bytes in a message. The speed dials can also be used with
message blocking to restrict addresses t hat can send to the satellite modem and those to which
the satellite modem can send.
NOTE: For the Digi m10 JumpStart Kits, Digi provides automatic e-mail forwarding for
messages with speed-dial destinations. This greatly simplifies your overall evaluation and
development experience by allowing you to def i ne speed dial configurations online at any given
time, without changing the actual satellite service provisioning of your modem. Please refer to the
online help of the Digi Satellite Dashboard application for more information about the speed dial
forwarding. If you have any additional questi ons, please contact Digi technical support.”
3.10 Message Acknowledgments
Acknowledgments allow a customer to have confidence that SC-originated messages have
reached the Gateway successfully. While ORBCO MM’s implementation of extended SMTP
(ESMTP) allows for delivery notification information for SC-originated messages, the destination
mail server and any mail servers relaying mail al ong the path to the destination server must also
support the extended version of the protocol. In cases where the customer hosts support ESMTP,
delivery notification is returned to the origi nating SC in a System Response. In other cases,
results described in a System Response as referri ng to delivery to the message recipient can be
misleading. An acknowledgment from the ORBCOMM Gateway is implicit in the delivery protocol
for MESSAGES, and is implemented regardless of the specified acknowledgment l evel. No
acknowledgment by the Gateway is available for Global Grams. For Data Reports, the service
type specified for the message determines t he acknowledgment level.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 16 of 26
0
No Acknowledgment
Acknowledgment is generated only if message fails
to reach the GCC.
Acknowledgment is generated when message has
successfully reached (or failed to reach) t he G CC.
Acknowledgment is generated only if message fails
to reach recipient.
Acknowledgment is generated when message has
recipient.
acknowledgments between the SC and any device terminal equipment in use.
Service Level Description
1
2
3
4
Note that service levels 0 and 1 are only used for SC -originated traffic and refer to
Table 1: Message Acknowlegements
More documentation can be found on the kit instal lation CD. To learn more, navigate to
C:\Program Files\Digi\Digi m10 JumpStart Kit\documents. For more information please refer to
the ORBCOMM Messaging Services Description > Appendix B SMTP Acknowledgment S erv i ce
successfully reached (or failed to reach) t he
3.11 Alternate Terminating Address (ATA) /
Message Forwarding
Message forwarding allows copies of all SC-termi nated messages to be sent to an alternate
terminating address (ATA). Any valid e-mail address can be set as the ATA, and any of three
forwarding rules can be applied: carbon copy, co nditional, or unconditional. The appropriate
address and rule should be specified when t he sat el li te modem is provisioned.
3.12 Delivery Plan
A delivery plan is the scheme the ORBCOMM gateway uses to attempt delivery of SC-terminated
messages. Delivery plans have four main characteristics:
• Automatic delivery attempts: the number of times, immediatel y upon receipt and at one-
minute intervals, the ORBCOMM Gateway will attempt to deliver an SC-terminated message
• Time to hold: the maxim um time the ORBCOMM Gateway will hold the message before
returning it as undeliverable
• Deletion after fi n al attempt: whether the message should be del eted after the automatic
delivery attempts are exhausted, or held unti l the time to hold has been reached
• Use of piggybacking : whether a message delivery attempt should be triggered by
successful delivery of another message in either direction
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 17 of 26
3.13 GES-to-Satellite Channels
The RF links that connect an ORBCOMM Gateway GES to an ORBCOMM satellite use a single
57.6-kbps uplink and downlink channel that uses t he TDMA protocol. This protocol permits
simultaneous RF links between a single satell ite and several GES installations within the sat el lite
footprint. It also provides a virtually seamless hand-over of a satellite from GES to GE S under the
centralized control of the GMSS.
3.14 GES-to-GCC Channels
GES-to-GCC links will operate over 56-kbps or 64-kbps data lines. A typical installation consists
of a Channel Service Unit/Data Service Unit (CSU/DSU) with a V.35 interface at both ends.
TCP/IP IEEE 802.3 (Ethernet) packet routers, which provide link layer internetworking, connect
these interfaces to the GCC and GES facilities. The G E S process communicates with the GMSS
process using TCP/IP UDP packets.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 18 of 26
4. Digi Extended Packets
In addition to the ORBCOMM serial commands defi ned i n the ORBCOMM Serial Specification,
the following Digi Extended Packets are avail able to the host controller:
• Temperature Out of Bounds Packet
• Temperature Query
• Temperature Query Respo nse
• NVM Data Corrupt i on A l ert Packet
• Code Upgrade Pack et
• RTS/CTS Control Packet
The following sections provide details about t hese packets.
4.1 Temperature Out of Bounds Packet
Table 2: Temperature Out of Bounds Packet
0 0x05/0x06 Packet Header
1 0x18 Packet Type
2 Length0
3 Length1
4 Retry_count/ Pkt Sequence Number
5
6
7 Temp2
8 Temp3
9 Fletch0
10 Fletch1
Temp0
Temp1
Length of the packet
Temperature value
in little endian
format.(This is a 32
bit floating point
Fletcher Checksum
number)
NOTE: This packet is sent from the Digi m10 to DTE when temperature of the Digi m10
goes beyond the operating range (-40C to +85 C). DTE should p ower down the Digi m10 when
this packet is received.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 19 of 26
4.2 Temperature Query
0
0x85/0x86
Packet Header
1
0x19
Packet Type
2
Length0
3
Length1
4
Retry_count/ Pkt Sequence Number
5
Fletch0
Fletcher Checksum
6
Fletch1
The Temperature Query packet (see Table 3) is sent from the host controller to query the Digi
m10 temperature.
Table 3: Temperature Query Packet
Length of the packet
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 20 of 26
0
0x05/0x06
Packet Header
1
0x1A
Packet Type
2
Length0
3
Length1
4
Retry_count/ Pkt Sequence Number
5
Temp0
Temperature value in
6
Temp1
7
Temp2
8
Temp3
9
Fletch0
Fletcher Checksum
10
Fletch1
4.3 Temperature Query Response
The Temperature Query Response packet (see Table 4) is sent from the Digi m10 to the host
controller, indicating the satellite modem’s temperature in degrees Celsius.
Table 4: Temperature Query Response Packet
Length of the packet
little endian
format.(This is a 32
bit floating point
number)
NOTE: This packet is sent from the Digi m10 to DTE and it contains the current
temperature of the Digi m10 in degrees Celsius.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 21 of 26
4.4 NVM Data Corruption Alert Packet
Table 5: NVM Data Corruption Alert Packet
0 0x05/0x06 Packet Header
1 0x1B Packet Type
2 Length0
Length of the packet
3 Length1
4 Retry_count/ Pkt Sequence Number
5 Fletch0
Fletcher Checksum
6 Fletch1
NOTE: This packet is sent from m10 to DTE when NVM data is corrupted and the Digi m10
resets NVM data to factory defaults by itself.
4.5 Code Upgrade Packet
Table 6: Code Upgrade Packet
0 0x85/0x86 Packet Header
1 0x1C Packet Type
2 Length0
3 Length1
4 Retry_count/ Pkt Sequence Number
5 Fletch0
6 Fletch1
Length of the packet
Fletcher Checksum
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 22 of 26
NOTE: DTE should send this packet to m10 before initiating xmodem code upgrade
process.DTE receives LLACK in respo nse to this packet.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 23 of 26
4.6 RTS/CTS Control Packet
0 – Disable flow
1- Enable flow control
Table 7: RTS/CTS Control Packet
0 0x85/0x86
1 0x1D
Packet Header
Packet Type
2 Length0
3 Length1
4 Retry_count/ Pkt Sequence Number
5 0/1
6 Fletch0
7 Fletch1
The checksum for the received LLACK, in respo nse to DIGI m10 extended RTS/CTS
control packet sent by DTE, should be calculated for the first 5 bytes only.
Example:
On sending RTS/CTS enable/disable command, the LLACK that we receive is:
05 01 08 00 00 00 BD 35 and is 8 bytes in length.
However, in the above LL ACK response, the check sum should be calculated for the first 5 bytes
Length of the packet
Fletcher Checksum
control
only for verification and byte marked in red should be ignored. That means we should calculate
checksum for “05 01 08 00 00” only, and validate i t with the checksum embedded in the last two
bytes which is marked in green ( BD 35) in this exam pl e.
NOTE: DTE can enable or disable RTS/CTS flow control by sending the above packet .
DTE receives an 8 byte LLACK in response to the above packet.
Important:
1. Communication over USB will NOT work when RTS/CTS is enabled.
2. DTE should disable RTS/CTS flow control before connecting to the Digi m10
development board using USB.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 24 of 26
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 25 of 26
Appendix A: Update Firmware
1) Go to Start > program Files > Digi > Digi m10 Jumpstart Kit > Tools and
Click on “Firmware update”.
2) Once application starts, select COM port and the required firmware file (.ldr) from
saved location and click on Start button.
You will see following screen when your modem has upgraded successfully. Click to close
the firmware upgrade utility and start the Digi m10 dashboard application.
Digi m10 Technical Overview
Digi International, Inc. © 2009
Page 26 of 26
WARNING: Do NOT turn off your Digi satellite modem or remove any cables
during the firmware upgrade process. This may result in corrupted firm ware,
causing your satellite modem to be no longer functional!
Loading...