Used to reset a currently stopped program to step 1.
The value of each variable is also reset to zero (0).
This signal can be used only in the EXT. SIGNAL mode.
1. The PRG_RST signal should not be input together with
the STROBE, CYC_RST, STEP_RST or DO_RST signal.
Because the ACK signal is used in common, only the first
signal which is input becomes valid and all other signals
become invalid.
2. This signal cannot be used while AUTORUN (automatic
operation mode ON) is set ON.