It is normally not a problem, as normally only the controller sends command to devices, but if we want to sniff data on the bus, we will need to know the request before parsing the answer. There is no indication about the initial request in the response frame.
Regarding responses, all of them use header 0, which can be considered as an ACK packet. For instance, header 0xfe is the “Sample poll” header.Īny device that receives this one needs to respond with an ACK packet ie an empty response frame. The header field is the actual command sent to the device, it contains a single byte representing the action that must be taken by the destination device.Īll these headers are documented in the protocol specs and can take arguments that are added in the data field of a frame. All devices must process the request and respond with source address 0. The addresses are encoded in a byte, which means that a maximum of devices can be used on a single bus. This follows the talk I made at Defcon this year slides here: As multiple devices can be on the same bus, each of them has its own address on that bus so they don’t conflict with cctakl other. serial port – C# function equivalent to CCtalk protocol – Stack Overflow This article is the first part of a series about the ccTalk protocol.
#Cctalk Serial Interface software#
Whereas the task of writing software for full-blown networking. The OSI 7-layer network model is of limited use for a simple control protocol such as cctalk. The ccTalk protocol is used to transfer information and commands to various money processing device, including coin/bill acceptors and coin. It was thought that the security in a serial interface was so much better than a parallel one that no. The original ccTalk protocol did not use any kind of encryption.