h.fSignalGain inconsistent between protocol versions

[fcollman]

June 2011: In one specific case, a user recorded data with a recording protocol that may have been set up originally with pClamp 9.x. In this protocol, amplification of the signal via a Cyberamp (the meanwhile out-of-date analog programmable signal conditioner of Axon Instruments) had been set to 200. Internally, this registers as a value of 200 of parameter h.fSignalGain. However, over the years, the setup changed, the Cyberamp went, pClamp10 came, and the protocol was in all likelihood just adapted, leaving h.fSignalGain at 200 (and the data values produced by abfload too small by that factor) although the thing wasn't hooked up anymore. However, when openend in clampex, the data are properly scaled. So, either the axon programs ignore the values of h.fSignalGain (and h.fSignalOffset) or - more likely - there is a flag somewhere in the header structure that informs us about whether the gain shall apply (because the signal conditioner is connected) or not. At any rate, whenever you change hardware and/or software, better create the protocols from scratch.