TM S SmarTek Systems, Inc. TM S 14710 Kogan Drive Woodbridge, VA 22193 703-680-6554 Sales 410-315-9727 SmarTek Acoustic Sensor - Version 1 (SAS-1) Installation and Setup Guide Part-G SAS-1 Detailed Communication Formats 04 April 2003 Note: In all cases, do not work or position equipment over an active traffic lane. Working over active lanes presents a hazard to the installer and to travelers using the highway.
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Detailed SAS-1 Communication Message Formats This document lists and describes in detail the entire set of SAS-1 messaging formats. Every effort has been made to ensure the accuracy of the document relative to SAS-1 capability and operation. Command to SAS-1: Traffic Acoustic Image Reporting (SAS Monitor Mode=1) {SASxxxx,BTR=Strt_LD,No_LDs,LD_Step} All parameters are offset by +32 (20 Hex) and is ASCii character 27.
Chr(2)SASxxxxPPPLLVVVUUUWWWOOOSSSS LLVVVUUUWWWOOOSSSS LLVVVUUUWWWOOOSSSS LLVVVUUUWWWOOOSSSS LLVVVUUUWWWOOOSSSSChr(3) where PPP is the message position in the SAS-1 FIFO buffer, LL is the lane number, VVV is the total vehicle volume or count, UUU is the commercial truck count, WWW is the tractortrailer count, OOO is lane occupancy in percent, SSSS is average spe
2 to 8 9 to 11 12 13 14 15 16 17 18 7 Characters Sensor ID (i.e. SAS0001, SAS0002, etc.) 3 Characters Temperature (degrees F, 101, -12, +33, etc.) Byte No. of Current Detections + 32 Byte First Detection Index + 32 Byte First Detection Source Level + 32 Byte First Detection LD Index + 32 Byte Second Detection Index + 32 Byte Second Detection Source Level + 32 Byte Second Detection LD Index + 32 .......................Repeat Pattern for each detection..................
{SASxxxx,RELAY=Chr(33)} Command to SAS-1: Start Dual Zone Relay Signals Reporting {SASxxxx,DRLY=Comm_Mode} Comm_Mode ia a byte (1-Polled, 2-Periodic) and is offset by +32 (20 Hex). SAS-1 Response: Chr(2)SASxxxx<20 bytes>Chr(3) where SASxxxx is the sensor identification number (i.e. SAS0000, SAS0001, SAS0002, etc.), Chr (2) and Chr(3) are the start of message and end of message characters. The SAS-1 formats the vehicle presence relays in a multi-time point, bit serial format.
Chr(2)SASxxxx Chr(3) All parameters are bytes and are offset by +32 (20 Hex). T_Det is the max detection threshold byte ( Max Det Threshold (db)=(T_Det - 120)/4.0 ). Alpha is the smoothing time constant byte (Smoothing constant=Alpha/100).
,,,,,,,,,, ,} All parameters are bytes and are offset by +32 (20 Hex). For SAS-1 software versions SAS_131 and above, the Send Parameters command not only sends parameters to the SAS-1, but causes the parameters to be written to non-volatile flash memory. SAS-1 Response: No Response. Command to SAS-1: Set SAS Baud Rate {SASxxxx,BAUD=Baud_Rate} Baud_Rate is a byte and is offset by +32 (20 Hex).
SAS-1 Response: Chr(2)SASyyyyChr(3) SASyyyy is the SAS-1 ID (ASCii) Each connected SAS-1 responds to the above command with a 0.5 second delay corresponding to its SAS ID. For example, SAS0001 responds after 0.5 second, SAS0002 responds after 1.0 seconds, SAS0003 responds after 1.5 seconds, and so on. Command to SAS-1: Change SAS-1 ID {SASxxxx,CHGID=SASyyyy} SASxxxx is current ID and SASyyyy is new ID. SAS-1 Response: Chr(2)OKChr(3) “OK” is ASCii.
When SAS-1 is set to FLOW mode, the AZDET mode, the RELAY mode, or the DRLY mode, this command must be sent to the SAS-1 after every other output message or SAS-1 will stop and fall back (after 5 minutes) to default operation as specified by the D_MODE parameter. SAS-1 Response: Continue the flow of data/messages from SAS-1 Command to SAS-1: RESET SAS-1 {SASxxxx,RESET} SAS-1 Response: Chr(2)OKChr(3) (“OK” is ASCII) followed by: Chr(2)SmarTekSystemsSAS-1Rev.
Repeat Sending Line 1 of Code File. The above process is continued for each line of the Code File until the End of the File is reached or an unrecoverable error occurs during the transfer at which time, SAS-1 Response: Chr(2)DONEChr(3) Indicates SAS-1 received all data correctly. SAS-1 Response: Chr(2)ABORTChr(3) Indicates SAS-1 aborted the process. SAS-1 Response: Chr(2)WRFAILChr(3) Indicates the write to non-volatile memory failed.
Chr(2)mm-dd-yyyy,hh:mm:ssChr(3) Command to SAS-1: Download Archive Data From the SAS-1 {SASxxxx,GDATA} SAS-1 Response: Chr(2)[Data Archive Record]Chr(3) Data Receiver Response: Chr(2)OKChr(3) “OK” to send the next archive record Chr(2)NOT_OKChr(3) Resend the archive record Chr(2)DONEChr(3) All archive records received “OK” Chr(2)ABORTChr(3) Unrecoverable error, end the process.
Line 1 of Header Record File (Intel Format) is sent to SAS-1. SAS-1 Response: Chr(2)OKChr(3) If record is received with no errors, Chr(2)NOT_OKChr(3) If record is received with errors. If SAS-1 Response is “OK” then: Line 2 of Header Record File is sent to SAS-1, Else If SAS-1 Response is “NOT_OK” Then Repeat Sending Line 1 of Header Record File.
archiving begins after the next full data write period. For example, let the archive period be set at 15 minutes and the SAS-1 Set Date and Time command be sent at 1:01:55 PM. The first archive record would be captured at 1:30:00 PM (data collected for interval 1:15 to 1:30) and the SAS-1 would write the archive records at 2:15:00 PM. The SAS-1 captures four (4) intervals of data before writing the data to non-volatile flash memory. The time stamp for each record corresponds to the end of the data interval.