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Summary of Contents for Sunsea AIoT SIMCom SIM800 Series
- Page 1 SIM800 Series_Multiplexer _Application Note GPRS Module SIMCom Wireless Solutions Limited Building B, SIM Technology Building, No.633, Jinzhong Road Changning District, Shanghai P.R. China Tel: 86-21-31575100 support@simcom.com www.simcom.com...
- Page 2 SIM800 Series_Multiplexer_Application Note_V1.04 Document Title: SIM800 Series_Multiplexer_Application Note Version: 1.04 Date: 2020.06.15 Status: Released GENERAL NOTES SIMCOM OFFERS THIS INFORMATION AS A SERVICE TO ITS CUSTOMERS, TO SUPPORT APPLICATION AND ENGINEERING EFFORTS THAT USE THE PRODUCTS DESIGNED BY SIMCOM. THE INFORMATION PROVIDED IS BASED UPON REQUIREMENTS SPECIFICALLY PROVIDED TO SIMCOM BY THE CUSTOMERS.
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Page 3: About Document
SIM800 Series_Multiplexer_Application Note_V1.04 About Document Version History Version Date Owner What is new 1.00 2013-10-28 Ming.yang New version 1.01 2014-06-30 Haibing.chen Chapter Scope, Add projects Chapter 2.6,Add note 1.02 2016-11-17 Wenjie.lai Scope 1.03 2019-08-12 Yulong.zheng Modify format of UA frame 1.04 2020-06-15 Yizhe.Tan... -
Page 4: Table Of Contents
SIM800 Series_Multiplexer_Application Note_V1.04 Contents About Document ..........................3 Version History ............................3 Scope ..............................3 Contents ..............................4 Introduction ........................... 6 Purpose of the document ......................6 Related documents ........................6 Conventions and abbreviations ....................6 Multiplexer Introduction ....................... 8 Multiplexer Design Purpose ...................... - Page 5 SIM800 Series_Multiplexer_Application Note_V1.04 Data Channel ..........................17 About Flow Control ........................17 Samples for Frame Structure ....................18 3.10 Transmission Bit Sequence ...................... 19 MUX Examples ..........................20 Establish Channels ........................20 Frame Transmission ......................... 22 Power Saving Mode and Wake Up ................... 22 Flow Control ..........................
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Page 6: Introduction
SIM800 Series_Multiplexer_Application Note_V1.04 1 Introduction Purpose of the document Based on module AT command manual, this document will introduce SIMCom multiplexer protocol and the technical details of how to make use of it. Developers could understand and develop application quickly and efficiently based on this document. Related documents [1] SIM800 Series AT Command Manual [2] Digital cellular telecommunications system (Phase 2+) - Page 7 SIM800 Series_Multiplexer_Application Note_V1.04 Unnumbered Information command and response Power Saving Control Multiplexer Close Down Modem Status Command Terminal Equipment Mobile Station Flow Control Ready To Communicate Ready To Receive Incoming Call Indicator Data Valid Parameter Negotiation FCon Flow Control On Command FCoff Flow Control Off Command Non Support Command...
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Page 8: Multiplexer Introduction
SIM800 Series_Multiplexer_Application Note_V1.04 2 Multiplexer Introduction Multiplexer Design Purpose A device using GPRS or GSM data may wish to receive and transmit multiple streams of data simultaneously. These are Command data (AT commands), GPRS data and GSM circuit switched data (CSD). -
Page 9: Restrictions
SIM800 Series_Multiplexer_Application Note_V1.04 SIMCOM Multiplexer is established upon system transmission device layer (Commonly serial port). Data streams are addressed with DLCI value and encapsulated in frames based on GSM 0710 protocol (Chapter 2, SIMCOM Multiplexer Protocol) and transmitted through interface provided by transmission device layer. 2.3 Restrictions ... -
Page 10: Simcom Multiplexer Protocol
SIM800 Series_Multiplexer_Application Note_V1.04 3 SIMCOM Multiplexer Protocol SIMCom Multiplexer protocol provides a data transmission mechanism by establishing DLC between TE and MS. Several DLC can be set up. Each one is independent to one another and has its own management of buffer and flow control. -
Page 11: Address Flag Field
SIM800 Series_Multiplexer_Application Note_V1.04 The C/R (command/response) bit identifies the frame as either a command or a response. The DLCI is used to identify an individual data stream as well as channels between TE and MS. Multiple DLCIs shall be supported but the number is implementation-specific. The DLCIs are dynamically assigned. 3.1.3 Address Flag Field The content of the control field defines the type of frame. -
Page 12: Information Field
SIM800 Series_Multiplexer_Application Note_V1.04 3.1.5 Information Field The information field is the payload of frame and carries the user data information (e.g. AT Command and PPP data packet). The field is octet structured. The information field is only present in UIH frames. 3.2 Frame Type 3.2.1 SABM SABM is command frame and shall be used to establish DLC between TE and MS. -
Page 13: Disc
SIM800 Series_Multiplexer_Application Note_V1.04 3.2.3 DISC DISC is command frame and shall be used to close down DLC. Prior to acting the command, the receiving station shall confirm the acceptance of the DISC command by the transmission of a UA response. Please see the diagram above and refer to 3.6 for more details. -
Page 14: Closing Down Dlc
SIM800 Series_Multiplexer_Application Note_V1.04 reply with a DM frame with the F-bit set to 1. Please refer to 3.1 for more details. 3.4 Closing Down DLC The release of a DLC will be initiated from by the transmission of a DISC frame with the P-bit set to 1. Confirmation of the DLC release is signaled by MS sending a UA frame with the F-bit set to 1. -
Page 15: Psc
SIM800 Series_Multiplexer_Application Note_V1.04 3.6.1 PSC Message type coding octet: Hex value is 0x43(Command), 0x41(Response) The EA bit is always set to 1. The length field in PSC message frame is 0. It has no value octet. 3.6.2 CLD Message type coding octet: Hex value is 0xC3 (Command), 0xC1 (Response) The EA bit is always set the 1. -
Page 16: Msc
SIM800 Series_Multiplexer_Application Note_V1.04 3.6.4 MSC MSC message frame is designed to convey virtual V.24 control signals. It has one mandatory control signal byte and an optional break signal byte. MSC shall be sent prior to any user data after a creation of a DLC. Message format is: Type Length... -
Page 17: Fcon
SIM800 Series_Multiplexer_Application Note_V1.04 3.6.6 FCon Message type coding octet is： Hex value is 0xA3 (Command), 0xA1 (Response). The length byte contains the value 0 and there are no value octets. 3.6.7 PN,NSC,RPN,RLS,SNC Not Supported. 3.7 Data Channel SIMCOM multiplexer data channels shall be used to transmit user data streams such as AT command data, GPRS data and GSM CSD data streams. -
Page 18: Samples For Frame Structure
SIM800 Series_Multiplexer_Application Note_V1.04 Whereas, set to 0 to inform recovery of receiving frames. TE will send MSC message to MS with FC bit set to 1 in V.24 control signals when refuses to accept frames. Whereas, set to 0 to inform recovery of receiving frames. When receiving MSC, MS will feed back MSC response to indicate recover data transmission. -
Page 19: Transmission Bit Sequence
SIM800 Series_Multiplexer_Application Note_V1.04 3.10 Transmission Bit Sequence Transmission is based on 1 start bit, 8 data bits, 1 stop bit, and no parity. www.simcom.com 19 / 25... -
Page 20: Mux Examples
SIM800 Series_Multiplexer_Application Note_V1.04 4 MUX Examples Establish Channels ： Step 1 Launch Multiplexer Data Step Direction Comment TE<——>MS TE launches MS 61 74 2B 63 6D 75 multiplexer function by ——> 78 3D 30 0D 0D 0A AT+CMUX=0<CR><LF> AT command 4F 4B 0D 0A 0D 0A AT+CMUX=0<CR><LF>O K<CR><LF><CR><LF>... - Page 21 SIM800 Series_Multiplexer_Application Note_V1.04 Data Direction Step Comment TE<——>MS TE requests to establish ——> F9 07 3F 01 DE F9 DLCI1 using SABM frame MS feeds back UA for receiving SABM <—— F9 07 73 01 15 F9 accepts to create DLCI 1 [note 4] MS send UIH frame MSC F9 01 EF 09 E3...
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Page 22: Frame Transmission
SIM800 Series_Multiplexer_Application Note_V1.04 Note 5: The bit means the channel of the MSC message send to. Frame Transmission After establishment of control channel and data channels, TE and MS can transmit data through UIH frames between each other. Data Direction Step Comment TE<——>MS... -
Page 23: Flow Control
SIM800 Series_Multiplexer_Application Note_V1.04 MS feeds back PSC message F9 03 EF 05 41 01 PSC Response <—— through DLC 0 F2 F9 Frame MS enters power saving mode Note Wake up Set DTR low NOTE Power Saving Mode could be launched after AT+CSCLK=1 and then set DTR high. Flow Control Data Direction Step... -
Page 24: Dealing With The Wrong Frame
SIM800 Series_Multiplexer_Application Note_V1.04 TE sends FCon message through DLC 0 to indicate ——> F9 01 EF 05 A3 01 93 F9 recovery of data transmission Dealing with the Wrong Frame After successful establishment of data channels, Data transmission between TE and MS is normal. Data Direction Step Comment... - Page 25 SIM800 Series_Multiplexer_Application Note_V1.04 accept TE sends DISC frame to ——> F9 0F 53 01 3f F9 request closing down DLC 3 MS feeds back UA frame to <—— F9 0F 73 01 50 F9 accept TE sends DISC frame to ——>...
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