| 摘要 |
A method for use in communicating message between downhole equipment and surface equipment, the method comprising receiving a signal including a message that corresponds to an initial message and a check code that corresponds to an initial check code, the initial check code being a function of the initial message; and decoding the initial message using the received message and the received check code. To decode the message, certain signal parameter values are assumed, for example signal length and/or offset level, and then used to process the received signal to give a temporary message and a temporary check code. The temporary message is then processed using the function applied to determine the initial check code to provide a calculated check code. This is then compared with the temporary check code. In the vent that there is a match, the temporary message is identified as being a real message. In the event that there is no match, one or more of the parameter values are varied and the process is repeated iteratively until either there is a match or all possible parameter values have been checked. |
