I installed PSW with help from Tech Support yesterday and it's working OK.
Today I installed PWL, apparently successfully, but it seems to be faulty, or provoking a fault in the h/w unit itself. This occurs during the settings stage, regardless of whether or not any signal input is connected.
It's illustrated by this series of screenshots, in which I accept the defaults in setting up a new file. At stage 5, the unit starts audibly 'chattering', presumably an internal relay, and the LED simultaneously flashes.
Naturally this is a Saturday! So unless I discover the cause myself meanwhile (and I've been trying for several hours already), or I get a solution by email or in the forum, I will 'phone on Monday to discuss.
Terry, East Grinstead, UK