4 Digit count up/down with memory. It cyclically count up/down till a maximum of 9.999 units. It includes the memory function which allow to store in an internal Eprom the last data when the power supply is stopped.
CD-6 modules are Count up and Count down with pre-selection and relays output. Thansk to a switch you could count up or count down impulses closing contacts on the signal input or injecting external signal.