To extend the daily range of DCVG surveying and carry out CIPS (or the two techniques as a combined but separate one pass survey), it is important that the multiple Interrupters used to switch the CP ON and OFF are synchronised. Also it is very important that the CIPS data logger is synchronised with the Interrupters.

DCVG Ltd. have developed techniques where both Interrupters and CIPS data loggers, each having its own satellite aerial, synchronise using the code from the one second pulse sent out by the NAVSTAR satellite system. An internal computer, in each Interrupter or Data Logger, recognises the specific GPS time signal, so when installed in rectifiers, many kilometres apart and at different times of the day, are all able to recognise the same second of the day to initiate the ON/OFF switching sequence. Re-synchronisation occurs every five seconds to continually reconfirm the timing sequence and remove any possibility of timing drift, but more important be able to log GPS Co-ordinates and time for subsequent analysis. (One common problem with older more crude crystal controlled interrupters is the significant timing drift that can occur during one day).

Accurate synchronisation of all CIPS equipment is very important when carrying out CIPS at the DCVG pulse frequency of 0.45 ON, 0.8 OFF.

Synchronisation is not a fundamental requirement for Analogue DCVG surveys. However, on multiple Transformer Rectifier pipelines, switching more than one rectifier at a time is of distinct advantage in the practical application of the technique.