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In the following we give the scan dead times for different device selections. The scan device is dummy, the sample time is 1s, the wait time is 0s. The scans consist of 11 points from 0 to 10. The option “Smart listbox update” is selected. Here are the numbers:
| Devices | Dead time [%] |
| C1 - C4 | 2 |
| C1 - C4, VC2( random()) | 4 |
| C1 - C4, MCA1 (2048) | 10 |
| C1 - C4, MCA1 - MCA7 (2048) | 35 |
| C1 - C4, SCA1 - SCA7 | 29 |
“C1 - C4” means that counter C1, C2, C3 and C4 are selected and displayed. “VC2( random())” means that the virtual counter VC2, which happens to return a random number, has been selected and displayed. “MCA1 (2048)” means that the 2048 channels of MCA1 are read and displayed. “SCA1 - SCA7” means that 7 regions of interest have been defined. They are read and displayed.
It may be interesting to compare these numbers with those that have been generated using the old VT100-style menus: C1 - C4, 0.4%, C1 - C4, MCA1, 8.3% and C1 - C4, MCA1 - MCA7, 31%.
To conclude: the PerlTk interface adds dead time in the order of 2 - 4%.
Note that the Online manual contains some discussion about how to speed-up scans.