Mirror M0 Retracted Limit Switch

The interlock uses the N.O. contacts of the mirror-retracted limit switch (making ``ripped cable'' = ``mirror in'') whereas the E500 uses the N.C. contacs of the limit switch. Therefore, other than in the old X1A interlock manual, the E500 operates independent from the interlock.

The horizontal translation axis motor (the "white coded axis") of the LBL mirror M0 has had its fully retracted ("C.W. limit") limit switch wiring modified. The reason for this is because of the differing wiring requirements between the X-1A interlock system and the the E500 stepping motor drivers. At the LBL mirror M0 wiring harness, a "M0 retracted" connector is provided with the following pinouts:

Pin 1:	Mirror retracted (common)	(from switch)
Pin 2:	Mirror retracted (normally open)	(from switch)
Pin 5:	Mirror retracted (normally closed)	(from switch)
Pin 3:	Mirror retracted (common)	(to E500)
Pin 4:	Mirror retracted (normally closed)	(to E500)

Pins 1, 2, and 5 are directly tied to the mirror M0 retracted limit switch. However, Pins 3 and 4 are not. When powered on, the X-1A interlock system will close the circuit between Pins 3 and 4 when the mirror M1 is not fully retracted. If, however, the X-1A interlock system is powered off for some reason, this function must be duplicated by a jumper which ties together:
        Pin 1 $\rightarrow$ Pin 3
        Pin 5 $\rightarrow$ Pin 4
Thus, jumpering pin 1 to pin 3 and pin 5 to pin 4 will restore normal limit switch operation to the E500 when the interlock is not powered on.