User's Manual
    PMAC VME Hardware Reference Manual 
4  PMAC VME E-Point Descriptions 
E17A-E17D: Amplifier-Enable/Direction Polarity Control 
E Point and 
Physical Layout 
Location Description  Default 
E17A 
B2  Jump 1-2 for high TRUE AENA (1-4). 
Remove jumper for low TRUE AENA (1-4). 
No jumper installed
E17B 
C2  Jump 1-2 for high TRUE AENA (1-4). 
Remove jumper for low TRUE AENA (1-4). 
No jumper installed
E17C 
C2  Jump 1-2 for high TRUE AENA (1-4). 
Remove jumper for low TRUE AENA (1-4). 
No jumper installed
E17D 
C2  Jump 1-2 for high TRUE AENA (1-4). 
Remove jumper for low TRUE AENA (1-4). 
No jumper installed
Low-true enable is the fail-safe option because of the sinking (open-collector) ULN2803A output driver IC. 
E22 - E23: Control Panel Handwheel Enable 
E Point and 
Physical Layout 
Location Description  Default 
E22 
C2  Jump pin 1 to 2 to obtain handwheel encoder signal 
from front panel at J2-16 for CHB2 (ENC2-B). 
No jumper 
E23 
C2  Jump pin 1 to 2 to obtain handwheel encoder signal 
from front panel at J2-22 for CHA2 (ENC2-A). 
No jumper 
With these jumpers ON, no encoder should be wired into ENC2 on JMACH1. Jumper E26 must connect pins 
1-2, because these are single-ended inputs. This function is unrelated to the encoder brought in through Acc-
39 on J2. 
E24 - E27: Encoder Single-Ended/Differential Control 
E Point and 
Physical Layout 
Location Description  Default 
E24 
D2  ENC 4 through 1: 
Jump pin 1 to 2 to tie complementary encoder 
inputs to 2.5V. 
1-2 Jumper 
installed for E24 - 
E27. 
E25 
D2  Jump pin 2 to 3 to tie complementary encoder 
inputs to 5V. 
For no encoder connection:  Jump pin 1 to 2. 
E24: ENC 4 
E25: ENC 3 
E26: ENC 2 
E27: ENC 1 
E26 
D2  For single-ended encoders: Jump pin 1 to 2. 
For differential line-driver encoders: Do not care. 
E27 
D2  For complementary open-collector encoders: Jump 
pin 2 to 3. 










