Adaptec AHA-1510A - Manual (Page 38)

3-4
AHA-1510A/20A Series User’s Guide
AHA-1510A/20A Series User’s Guide
Stock Number: 510400-00, Rev. C
Page: 3-4
Print Spec Number: 491842-00
Current Date: 11/18/94
ECN Date: 11/29/94
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
A
A
A
A
A
A
A
A
A
A
A
A
A
A
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
A
A A
A
A
A
A
A
A
A
A
A
A
A
A
Termination for External Devices Only
When only external devices are connected to the host adapter, the
last device on the external chain of devices should be terminated
and the host adapter should be terminated, as shown in Figure 3-3.
Termination for Internal and External Devices
When both internal and external devices are connected to the host
adapter, the last external device and the last internal device should
be terminated, and you should remove the three terminators (i.e., dis-
able termination) on the host adapter, as shown in Figure 3-4.
Caution: If you replace the host adapter terminators,
make sure you maintain correct orientation. The dot
on the upper left corner of the resistor must align
with pin 1 of the socket.
External device
No termination
Host adapter
Terminators
installed
External device
No termination
External device
Termination enabled
Figure 3-3. Connecting External Devices Only
External device
No termination
Host adapter
Terminators removed
Internal device
No termination
Internal device
Termination
enabled
External device
No termination
External device
Termination enabled
Figure 3-4. Connecting Internal and External Devices