User`s guide

A-2 External Power Line Transceivers
Electrical Interface to the PCC-10 Network Port
There are a few design issues which should be taken into consideration when
designing an external transceiver pod:
• Pin 1 must be grounded when a pod is connected to inform the PCC-10 card of
the presence of an external transceiver.
• Source termination of 82• • ±5%, 1/4W is required on all lines driven from a
pod back to the PCC-10 card.
• The Vcc drop resulting from resistance of the 28AWG pod cable must be taken
into consideration when determining cable length.
• The pod cable may be shielded or unshielded as required by EMC considerations.
• Note that BUF_CP0 — BUF_CP4 are TTL compatible at the pod connector (see
table 4.2). HCT logic buffers should be used in the pod when interfacing to these
lines.
• If the pod ground and cable shield need to be connected (to improve ESD or EMI
performance of the pod) then the additional circuitry shown in figure A.2 should
be used.
PCC-10 External Power Line Transceiver Connection
The PCC-10 card can be connected to most networks provided that the appropriate
network transceiver interface pod is attached to the network port. The connections
for a power line network interface pod are provided as an example for developers.
PL-20 Network Connection
Figure A.1 shows a block diagram for interfacing the PCC-10 card to a
PLT-20/PLT-21 Power Line Transceiver.
If the transceiver is removed from an active PCC-10 card configured for special-
purpose mode, the PCC-10 card will reset once. Until the transceiver is re-
connected, the Media Access Control (MAC) layer of the Neuron Chip in the
PCC-10 card will continually attempt to re-initialize the missing transceiver. In
this state, the PCC-10 card can be tested. However, any other messaging,
including service pin messages, will cause the PCC-10 card to reset due to a full
message buffer (see chapter 2 for use of Diagnostic Commands).