This is a question we’ve been getting with increased frequency and will be answered with references as completely as possible. Several publicly available links are provided herein for more in-depth information.
The AirPro is a patent-pending, remotely-controlled, OEM compliant scan-tool and programming system that is directly connected to a vehicle.
The AirPro has approximately 98% vehicle coverage from 1996 to current (2017) because of its unique combination of OEM and independent proprietary software. Yes, the AirPro uses both OEM and independent proprietary diagnostic software. The scan-tool software is directly connected to a vehicle and remotely accessed by AirPro Diagnostics’ highly skilled diagnostic specialists to interface with a vehicle’s control module network and systems to perform the various diagnostic procedures required on today’s vehicles.
The AirPro can; read and clear diagnostic trouble codes (DTC) on all systems, calibrate or program modules within OEM parameters, display live data streams (inputs and outputs), command bi-directional controls (the ability to make the controllers do things outside of a vehicle’s normal operations) for customized testing and diagnostics well beyond just displaying a list of trouble codes.
The asTech device is NOT a scan-tool. The asTech is an aftermarket interface interpreter (translator) which converts vehicle communication protocols to internet protocol (TCP/IP). Two asTechs, in two separate locations, are required for a remote connection to a vehicle from a scan-tool which is linked together by a non-OEM validated server via the Internet for this to work. A publicly available copy of the patent and method is available for review here: https://www.google.com/patents/US8688313
Scan-tool functions and capabilities are reduced to less than their original design when converted and transmitted in this manner. The inability of any product to convert, transmit and reconvert, automotive protocol data, within a scan-tool’s functional timing parameters, along with inherent differences between automotive protocol communication requirements and TCP/IP communication protocol standards, cause this reduction.
The asTech device also limits scan-tool functionality to only those automotive protocols which have been developed for conversion, thus limiting vehicle or module coverage even further. Hence the need for a “coverage chart” http://AsTech.com/media/1185/cds-coverage-chart.pdf . One might ask, “if the asTech supports the Chrysler wiTECH factory tool, as claimed, then why is it shown as model dependent or won’t support scanning or programming services on ALL FCA vehicles as the wiTECH is designed?” The same should be asked for every other manufacturer shown with limited coverage on the asTech coverage chart.
Also see https://en.wikipedia.org/wiki/On-boarddiagnostics for publicly available definitions of several vehicle diagnostic and communication protocols
TCP/IP PROTOCOL SUITES
“TCP divides the data into proper sized chunks and then passes these chunks onto the network. It acknowledges received packets, waits for the acknowledgments of the packets it sent and sets timeouts to resend the packets if acknowledgements are not received in time. The term ‘reliable connection’ is used where it is not desired to lose any information that is being transferred over the network through this connection. So, the protocol used for this type of connection must provide the mechanism to achieve this desired characteristic.”
“For example: while downloading a file, it is not desired to lose any information(bytes) as it may lead to corruption of downloaded content.”
“UDP provides a comparatively simpler but unreliable service by sending packets from one host to another. UDP does not take any extra measures to ensure that the data sent is received by the target host or not. The term ‘unreliable connection’ are used where loss of some information does not hamper the task being fulfilled through this connection. For example, while streaming a video, loss of few bytes of information due to some reason is acceptable as this does not harm the user experience much.”
“At the next lower layer, IP adds its own information over the data coming from transport layer. This information would help in packet travelling over the network. Lastly, the data link layer makes sure that the data transfer to/from the physical media is done properly. Here again the communication done at the data link layer can be reliable or unreliable.”
See http://www.thegeekstuff.com/2011/11/tcp-ip-fundamentals/ to reference the above:
“Packet loss is typically caused by network congestion. When content arrives for a sustained period at a given router or network segment at a rate greater than it is possible to send through, then there is no other option than to drop packets. If a single router or link is constraining the capacity of the complete travel path or of network travel in general, it is known as a bottleneck.”
“Packet loss can be caused by several other factors that can corrupt or lose packets in transit, such as radio signals that are too weak due to distance or multi-path fading (in radio transmission), faulty networking hardware, or faulty network drivers. Packets are also intentionally dropped by normal routing routines (such as Dynamic Source Routing in ad hoc networks, ) and through network dissuasion technique for operational management purposes.”
See https://en.wikipedia.org/wiki/Packet_loss to reference the above
To connect to either a scan-tool or a vehicle for internet protocol conversions and transmission of scan-tool commands over the internet to a vehicle and/or for a vehicle to respond to a scan-tool for data requests or output commands, such as critical calibrations or tests, the internet and IT infrastructure conditions need to be perfect for reliability. When conditions are desirable valuable data and procedures can be performed. However, the Internet and conversion of data is not reliable enough for anyone to claim true OEM scan-tool functionality regardless of the tool being used.
Because of time delays, and the inherent fluctuation of internet transmission or congested internet traffic, data packets can be dropped, re-arranged or delivered out of order causing skewed, inaccurate or incomplete data transmission between a vehicle and a scan-tool when transmitted over the internet.
Therefore, the reliability of the asTech to accurately calibrate vehicle safety systems on a consistent basis can be compromised due to these ongoing, uncontrollable factors.
Hopefully this information helps define the differences between the AirPro and the asTech and helps explain AirPro Diagnostics’ ability to provide OEM-level diagnostic, calibration and pre- or post-scanning services to the collision industry.