pest.txt

Nov. 10, 1999

Pest data format

byte     Desc.           Value
-----------------------------------------
1        Sync            0xC3
2        Sync            0x9A

3        Byte count (LSB)
4        Byte count (MSB)

5-8      Seconds since
         midnight Jan. 1 1970
         byte 5 = LSB, byte 8 = MSB

9        Time (ms) (LSB)
10       Time (ms) (MSB)

11	 PEST status bits
		Bit 4 = Shutdown complete,
		Bit 2 = CEP relay ON,
		Bit 0 = PinPull relay ON

12	PEST data packets available. Set bit indicates packet available
		Bit 3 = CEP, 
		Bit 2 = RM400,
		Bit 1 = House Keeping,
		Bit 0 = DIFP		
		
If byte 12 bit 1 set

	Housekeeping Data (20 bytes total)		

If byte 12 bit 3 set
	CEP data (192 bytes total)		

If byte 12 bit 0 set
        DIFP byte count MSB		
	DIFP byte count LSB		
	DIFP data (Worst case is 392 bytes)

If byte 12 bit 2 set

	RM400 data (64 bytes)

Last two bytes of data packet

      Checksum (LSB)
      Checksum (MSB)

Notes:

The byte count (bytes 3 & 4) includes all bytes including the two sync
characters and the two checksum bytes.

CRC is calculated using all bytes except the two checksum
bytes. If you reverse the last two bytes (bytes 661 & 662 above)
they can be included in the CRC and a valid CRC value would then
be zero (0).


********************************************************************
* The examples still do not match the above format. I will try to  *
* get some valid sample data in the next two weeks!                *
*                                                                  *
* I am still working on getting the actual data format and scaling *
* factors.                                                         *
********************************************************************

Example:
-------------------------------------------------
Example 1.

c3 9a 22 00 ca af 0b 38 e6 00 00 20 b8 02 bc 02 
be 02 bb 02 f9 07 65 0e bc 0b 00 00 1c 00 00 00 
8a 76 

date: Mon Oct 18 17:39:54 1999
milliseconds: 230 
Total Bytes: 34
CRC: 0x768A

Example 2.

c3 9a e2 00 cf af 0b 38 e6 00 40 a0 ba 02 bb 02 
c0 02 b9 02 f9 07 67 0e bd 0b 00 00 1c 00 00 00 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
aa 4c 

date: Mon Oct 18 17:39:59 1999
ms: 230
Bytes: 226 
CRC: 0x4CAA

Example 3.

c3 9a ce 00 d6 af 0b 38 bc 02 40 80 fa de 00 02 
01 8c ff ff ff ff ff ff 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 88 9b 

Date: Mon Oct 18 17:40:06 1999
ms: 700
Bytes: 206
CRC: 0x9B88