Revision 1.0 STX3 Users Manual STX3 Users Manual 11/5/2013 Revision 1.
Revision 1.0 STX3 Users Manual Table of Contents 1 2 Introduction .................................................................................................................................................................... 3 1.1 Purpose ................................................................................................................................................................... 3 1.2 Applicable Documents .....................................................................
Revision 1.0 STX3 Users Manual 1 Introduction 1.1 Purpose This document describes the physical, electrical, and functional characteristics of the STX3 satellite transmitter module. The information contained in this document is intended to provide the end user with the necessary technical information required to use the module in a custom application. This document is intended to be used by engineers and technical management and assumes a general knowledge of basic engineering practices by the user. 1.
Revision 1.0 STX3 Users Manual 2 Application 2.1 Theory of Operation The STX3 operates on the Globalstar LEO satellite network. LEO (Low Earth Orbit) means that there are a number of satellites in low earth orbit that constantly orbit the planet and can communicate with Globalstar devices that are within range of its current position.
Revision 1.0 STX3 Users Manual Figure 3 Simplex Messaging Messages are composed of 1 or more 9-byte byte payloads. The STX3 can only transmit 99-byte on-air air messages, so user payloads greater than 9 bytes will require multiple on on-air packets to be transmitted for each user payload. There aree brief periods of time where there is no satellite in range of the simplex transmitters due to obstructions and/or satellite coverage geometry.
Revision 1.0 STX3 Users Manual The transmission sequence for a two-packet packet message using the default setting of 3 redundant transmissions is shown below. For normal conditions where the transmitter has an open view of the sky, this will result in a better than 99% chance that the message will be received. 2.2 Block Diagram The basic elements of a design utilizing the STX3 simplex transmitter are shown below. 11/5/2013 Revision 1.
Revision 1.0 STX3 Users Manual Figure 4 The STX3 provides separate power supply inputs. The digital power supply input (VDIG) is a low power input which powers the digital portion of the STX3. This provides the capability to leave the STX3 in a low power consumption cons state when the transmitter RF section is idle. The RF power supply input is a high power input which is only required while the STX3 is transmitting a data packet.
Revision 1.0 STX3 Users Manual 3 Physical Charactersistics Figure 5 Top View 11/5/2013 Revision 1.
Revision 1.0 STX3 Users Manual Figure 6 Recommended PCB footprint layout (dimensions in inches) 11/5/2013 Revision 1.
Revision 1.
Revision 1.0 STX3 Users Manual Parameter Test Conditions Min Typ Max Unit TX output power -40 40-85º C, Vcc=Vrf=3.3 volts, 50 ohm load 17.0 17.5 18.0 dB Transmit mode supply current -40 40-85º C, Vcc=Vrf=3.3 volts, 50 ohm load 315 325 350 mA Active mode supply current 25º C, Vcc = 3.3 volts 2.3 2.5 mA Standby mode supply current 25º C, Vcc = 3.3 volts 12 50 uA Sleep mode supply current 25º C, Vcc = 3.3 volts 8 40 uA 4 Application Programming Interface 4.
Revision 1.0 STX3 Users Manual 4.2 Serial Packet Mode This mode is the legacy mode of operation as implemented in the STX2 which consists of binary data packets. 4.2.1 Serial Packet Format Preamble Length Command Data CRC Fixed pattern 0xAA Total number of bytes in the serial packet including the preamble Command type (See Table 5 Serial Packet Type).
Revision 1.0 4.2.2 STX3 Users Manual Serial Packet Commands For all serial packet commands as described below: • • • • • • AA is the Preamble. NN is the Length. XX is an unspecified byte value CLSB is the least significant CRC byte CMSB is the most significant CRC byte If an improperly formatted command is received, the STX3 will return a NAK response: AA 05 FF A1 CB 4.2.2.1 Send Data (0x00) The Send Data command requests the STX3 to send from 1 to 144 data bytes over the Globalstar Simplex network.
Revision 1.0 STX3 Users Manual Where the ESN returned is 2300000. 4.2.2.3 Abort Transmission (0x03) The Abort Transmission command requests the STX3 to abort the current message transmit sequence over the Globalstar Simplex network. 0x03 header len Cmd CRC1 CRC2 AA 05 03 42 F6 Command: AA 05 03 42 F6 Response: AA 05 03 42 F6 4.2.2.
Revision 1.0 Command: STX3 Users Manual AA 05 05 74 93 Response: header Len 04 FW major AA 08 05 XX Example Response: FW minor XX CRC1 CRC2 CC CC XX AA 08 05 01 00 07 57 44 Where the firmware version returned is: 1.07 4.2.2.6 Setup (0x06) The Setup command requests the STX3 to use the specified current setup parameters. These are stored in non-volatile memory.
Revision 1.
Revision 1.0 STX3 Users Manual Where: • • • • Device Code : Board Revision: CPU Revision: Radio Revision: Example Response: Always 1 for STX3 STX3 hardware revision STX3 CPU revision STX3 radio revision AA 0A 09 00 01 00 8E 62 E5 5E Where the revision information returned is: • • • Board Revision: CPU Revision: Radio Revision: 11/5/2013 Revision 1.
Revision 1.0 STX3 Users Manual 4.
Revision 1.
Revision 1.0 STX3 Users Manual 4.4 AT commands Command Response Comments This command is used to check communication between the AT module and the host. OK STX3 is ready for normal operation ERROR STX3 is not ready for operation, an error condition exists Request product serial number identification AT+GSN? AT+CGSN? AT+GMM? +GSN: product serial number identification (ESN) ERROR Unable to retrieve ESN +GMM: STX3 Request model identification (hardware version).
Revision 1.0 STX3 Users Manual dd: decimal degrees, mm.mmmm minutes NS: hemisphere (N/S) Lng: dddmm.mmmm ddd: decimal degrees, mm.mmmm minutes EW: hemisphere (E/W) hhhhhh: hexadecimal value of 3 byte payload Example: AT+CMGSL=3025.9857,N,09005.2182,W,A53311 OK Message Burst In Progress ERROR Invalid message or modem error Cancel running transmission. AT+CANX Command OK (This command will never return an error. If no OK transmission is running, it will simply do nothing.
Revision 1.0 STX3 Users Manual OK Command OK, number of tries successfully set. ERROR Unable to set number of tries. Most likely reason is that the number requested was out of range. Must be 1 – 16. Request number of tries setting for bursts. AT+CBNT? +CBNT: = number of tries set for bursts. Set the minimum time between transmissions in the burst in AT+CBTMIN= seconds. Acceptable range is 5 – 300 seconds. Value will be truncated by the device to the nearest divisible of 5.
Revision 1.0 +RAREV: STX3 Users Manual Transmitter revision. 5 Test Modes The STX3 provides several test modes intended to aid in manufacturing testing and certification testing. All test modes are activated by grounding selective pins on the STX3 prior to applying power. Once power is applied, the STX3 will sample the states of the pins and based on the states of the pins, the STX3 will enter the selected test mode. For normal operation these pins must be left floating or in a high (logic 1) state.
Revision 1.0 STX3 Users Manual The channels are selected via the Rx and RTS pins as follows RX RTS Channel 0 0 B 0 1 C 1 0 D 1 1 Channel specified in the flash setup. To specify channel A, it must be the default channel specified in the flash setup. See Setup command for details. 11/5/2013 Revision 1.
Revision 1.0 STX3 Users Manual 6 REGULATORY APPROVAL The STX3 module has received regulatory approvals for modular devices in the United States and Canada. Modular device approval allows the end user to place the STX3 module inside a finished product and not require regulatory testing for an intentional radiator (RF transmitter), provided no changes or modifications are made to the module circuitry. Changes or modifications could void the user’s authority to operate the equipment.
Revision 1.0 STX3 Users Manual Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. The user’s manual should include the following statements: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules.
Revision 1.0 STX3 Users Manual FCC ID: L2V-STX3 ICES-003/(A/B) IC:3989A-STX3 R&TTE: TBR41 Complies with FCC standards. FOR HOME OR OFFICE USE 11/5/2013 Revision 1.
