Ex 13e 500serprogram

FCC ID: OU5340MT

Users Manual

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FCCID_155263

1 Serial Protocol for the STn00 and SRn00 devices Issue 2 Date 5/6/00 1 Introduction This document describes the serial protocol for re-programming the STn00 and SRn00 range of transmitter and receiver modules. There is an important difference between the VHF and the UHF products which concerns the Intermediate Frequency (IF) used. To differentiate between the ST and SR each has a unique product code. For the SRn00 this is 0F6 hex and for STn00 it is 0F5 hex. 2 Data Format Two baud rates are used for differing functions. Throughout this document, which one is being used is given. The two baud rates are: Baud rate 19,200, 8 data bits, 1 start bit, 1 stop bit, no parity Baud rate 1,200, 8 data bits, 1 start bit, 1 stop bit, no parity The internal PIC is running an RC clock which can vary considerable with component tolerance and temperature. To overcome this, a serial protocol is used which looks a the input waveform from the PC as a pulse, the duration of which determines whether the input data is a binary 1 or 0. If the baud rate is 19,200, the data byte to be transmitted to the radio is as follows: 0 (decimal) = binary 0 255 (decimal) = binary 1 During readback the data can vary and so must be interpreted as follows: Value < 241 (dec) = binary 0 Value $ 241 (dec) = binary 1 For the one data byte, 8 bytes must be sent representing each bit. If the baud rate is 1,200, then the data sent is a normal 8 bit byte. Note: throughout the document the value of the data is given assuming an RS232 interface. If TTL or similar logic levels are used then the data must be inverted.

2 3 Definitions The following give details of the terms used thoughout this document. 3.1 Fosc This is the value of the Reference Oscillator in the radio. This is NOT programmable and the value is not stored in EEPROM. Currently there are two types used by the ST/SRn00 units: 12.8 and 14.85 MHz. 3.2 Fc Fc is the Comparison Frequency used by the synthesizer in the radio. This is a programmable parameter, but care should be taken if it is changed, because the synthesiser hardware is optimized for certain values of Fc. The Fc in use with the ST/SRn00 family vary for the different applications, but is one of these discrete values: 5, 6.25, 10, 12.5 ,20 or 25 KHz (refer to Wood & Douglas for the actual values allowed). Fc is not directly stored as a number in the radio’s EEPROM. It is rather indirectly stored as the “Rvalue” (see below). 3.3 Rvalue This number is the result of the division: Rvalue = Fosc / Fc Since the ST/SRn00 family can have one of two Fosc: 12.8 or 14.85 MHz, the possible Rvalues for the radio are: If Fosc= 12.8MHz: RR1(5) = 2560 (dec), A00 (hex) RR1(6.25) = 2048 (dec), 800 (hex) RR1(10) = 1280 (dec), 500 (hex) RR1(12.5) = 1024 (dec), 400 (hex) RR1(20) = 640 (dec), 280 (hex) RR1(25) = 512 (dec), 200 (hex)

3 If Fosc= 14.85MHz: RR2(5) = 2970 (dec), B9A (hex) RR2(6.25) = 2376 (dec), 948 (hex) RR2(10) = 1485 (dec), 5CD (hex) RR2(12.5) = 1188 (dec), 4A4 (hex) RR2(20) = NOT possible (result is not integer no.) RR2(25) = 594 (dec), 252 (hex) From above it is clear that we have 11 possible values for the combination of 2 Fosc and 6 Fc’s. When the Rvalue is read from the unit the current Fc and Fosc. can be determined from these values. Note: Rvalue is stored as 2 bytes in EEPROM locations 61, 62 3.4 IF IF is the Intermediate Frequency of the receiver. Its value for the STn00 family is always zero, but for the SRn00 family is as follows: SRn00 with frequency range < 200 MHz:, “High Side” (+45 MHz) SRn00 with frequency range > 200 MHz, “Low Side” (- 45 MHz). STn00, any frequency IF = 0 Note: The IF value is not stored in the unit’s EEPROM. The type of ST or SRn00 must be known before programming can be carried out. 4 Channel Information and Storage For both the ST and SRn00 family, 16 random and 112 sequential channels can be stored in the non-volatile EEPROM memory area of the internal PIC processor. Channels 0 - 15 are stored individually in the EEPROM and channels 16 - 127 are calculated from the start frequency and the table step increment. In principle frequency is stored in a two byte format plus the high byte offset. The data stored is not the frequency itself, but the frequency divided by the Fc. In other words if the desired frequency for the random channel N is Freq(N), then the value stored is F(N) where F(N) is calculated as: F(N) = [Freq(N) + IF] / Fc The result is stored as: EEPROM(60) = int [F(N)/65536] *256 high byte offset EEPROM(N) = int [F(N)/256] - EEPROM(60) msb EEPROM(N + 16) = F(N)- [EEPROM(60) + EEPROM(N)] *256 lsb

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5 Or if a read-back is performed, the frequency on channel N is calculated as: Freq(N) = {{{[ EEPROM(60)+ EEPROM(N)]*256 }+ EEPROM(N+16)} - IDF }*Fc Hz where IDF = IF/Fc Similarly, for the Sequential table start, if desired frequency is FreqS, then: FS = [FreqS + IF] / Fc and the result is stored as: EEPROM(56) = int[FS/65536] *256 high byte offset EEPROM(57) = int[FS/256] - Eeprom(56) msb EEPROM(58) = FS- [EEPROM(56) + Eeprom(57)] *256 lsb The sequential table step is stored in location 57 as a multiple of Fc The sequential table is limited by the value stored in location 51 (0-111), but it can not exceed 111. If the value is > 111 then limit should be imposed as follows: MaxCh = EEPROM(51) Sequential ch. Limit If MaxCh > 111 then MaxCh = 111 Limit MaxCh Number to 111 ! endif If read-back is performed, the Start of the Sequential table is calculated as: SeqFreqStart = {{{[ EEPROM(56)+ EEPROM(57)]*256 }+ EEPROM(58)}- IDF }*Fc where IDF = IF/Fc this is Intermediate Frequency as a multiple of Fc And a sequential table step is: SeqFreqStep = EEPROM(59)*Fc [Hz]

6 5 EEPROM locations The PIC processor used in the STn00 and SRn00 units has an area of non- volatile memory EEPROM area. The contents of this data is given in the following table: Location Description 0 - 15 RX/TX div msbs 16 - 31 RX/TX div lsbs 32 - 47 not used 48 - 49 reserved 50 not used 51 is sequential table limit channel (0-111) 52 - 53 reserved 54 SETUP flags byte (default is FF). At the moment only relevant flag is one occupying bit no 1 and it is Serial or Parallel mode of operation. In Serial Mode Channel selected is the one defined in loc. 63 of EEPROM and is written using PC and serial interface. In parallel mode the switch in the unit (D0 to D2 lines) defines channel selected by the unit. In parallel mode only ch. 0 to 7 are accessible. 55 reserved 56 high byte offset for sequential table 57 sequential table start hi byte 58 sequential table start lo byte 59 sequential table step increment 60 high byte offset 61 Rvalue hi byte 62 Rvalue lo byte 63 serial channel selected Note: RESERVED locations are planned for future use NOT USED locations are not used with no plans for future use.

7 6 Command Types There are 3 types of packet to be sent to the radio from the PC: Short packet Long packet Direct packet These are described in the following sections. 6.1 Short packet This is used to send out single instruction to the radio to carry out functions like setting serial or parallel mode of operation, setting the serial channel number etc. For the short packet the 8 data bytes to be transmitted are: X product ID. For the SRn00 = 0F6 hex and for STn00 = 0F5 hex A EEPROM address or DATA1 B EEPROM data byte or DATA2 C not used (0) or DATA3 D not used (0) or DATA4 COM command byte chkH check sum hi byte } A + B + C + D + COM chkL check sum lo byte } Note: This data is sent out at 19200 baud as detailed in section 2. Each data byte within the packet should be separated by 10 to 15 msec. delay and the delay between 2 successive packets should be > 100 msec. The Command (COM) byte is defined as follows: 6.1.1 COM # 63 dec This denotes a long packet as described in section 6.2 for re-programming the EEPROM area. 6.1.2 COM = 64 dec This is the direct packet mode as described in section 6.3 and is used to change the channel of the unit.

8 6.1.3 COM = 66 dec This invokes the EEPROM read-back mode. After this command and a packet, the radio will respond with a reading back of the whole content of the EEPROM (64 bytes), one after another, without any address bytes etc. The data returned from the radio is at 19,200 as defined in section 2 of this document. 6.1.4 COM = 67 dec This invokes the single byte programming of the EEPROM where: A EEPROM address B EEPROM data This is used to change the mode of operation (Serial / Parallel) or for the setting of the serial channel number. As an example, to set the parallel mode of operation only, the following packet must be sent: X chr(0F6) hex for SRn00 or chr(0F5) hex for STn00 A EEPROM address byte chr(54 dec) B EEPROM data byte chr(255) for parallel C not used (0) D not used (0) COM chr(67) dec chkH chr(1) } chkL chr(120 dec) } for parallel mode (total check sum 376 dec.) For setting the serial channel, two packets must be sent. First the short packet must be sent with B data = 253, followed by the Direct packet as shown in section 6.3. 6.1.5 COM = 70 dec This resets the radio and should be sent at the end of the Long packet after the EEPROM contents have been re-programmed.

9 6.2 Long Packet The Long packet mode is intended to re-write the entire EEPROM area of the unit (64 locations). The format is similar to the short packet with a few differences as shown below: X Product ID. For the SRn00 = 0F6 hex and for STn00 = 0F5 hex A EEPROM DATA1 (from addr COM + 0) B EEEPROM DATA2 (from addr. COM +1) C EEPROM DATA3 (from addr. COM +2) D EEPROM DATA4 (from addr. COM +3) COM command byte = EEPROM address of the first data byte in a block chkH check sum hi byte }A + B + C + D + COM chkL check sum lo byte } 16 packets like above are expected once started, covering all 64 EEPROM locations. Note: This data is sent out at 19200 baud as detailed in section 2. There should be > 15 msec delay between bytes and > 100 msec. in between packets. A short packet (with COM = 70) should be sent at the end of the Long packet to reset the device. 6.3 Direct Packet Currently there is only one “Direct packet” in use and it is intended for the channel number change.. This 3 byte packet is sent at 1,200 baud as detailed in section 2. The form of the data packet is as follows: chr(64 dec) chr(Channel Number) chr(149 dec)


Document Created: 2019-07-04 00:44:28
Document Modified: 2019-07-04 00:44:28
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