Reference Manual

PMAC Mini PCI Hardware Reference Manual
8 Hardware Setup
A wrong setting of these jumpers will damage the associated output IC.
E101-E102: Motors 1-4 AENA/EQU Voltage Configure – The U37 driver IC controls the AENA and
EQU signals of motors 1-4. With the default sinking output driver IC (ULN2803A or equivalent) in U44,
these jumpers must connect pins 1 and 2 to supply the IC correctly. If this IC is replaced with a sourcing
output driver IC (UDN2981A or equivalent), these jumpers must be changed to connect pins 2 and 3 to
supply the new IC correctly.
Resistor Pack Configuration: Termination Resistors
The PMAC provides sockets for termination resistors on differential input pairs coming into the board. If
these signals are brought long distances into the PMAC board and ringing at signal transitions is a
problem, SIP resistor packs may be mounted in these sockets to reduce or eliminate the ringing.
All termination resistor packs have independent resistors (no common connection) with each resistor
using two adjacent pins. The following table shows which packs are used to terminate each input device:
Device Resistor Pack Pack Size
Encoder 1 RP15 6-pin
Encoder 2 RP18 6-pin
Encoder 3 RP23 6-pin
Encoder 4 RP25 6-pin