INDUSTRIAL I/O PACK SERIES
AVME9675A
VMEx64 bus 6U CARRIER BOARD
Acromag, Inc. Tel: 248-295-0310
- 37 -
http://www.acromag.com
- 37 -
https://ww.acromag.com
4.0 THEORY OF OPERATION
This section describes the basic functionality of the circuitry used on the
carrier board. Refer to the Block Diagram shown in the Drawing 4501-757
as you review this material.
4.1 CARRIER BOARD OVERVIEW
The carrier board is a VME64x bus slave board providing up to four industry
standard IP module interfaces for the AVME9670A
. The carrier board’s
VME64x bus interface allows an intelligent single board computer (VME64x
bus Master) to control and communicate with electronic devices that are
external to the VME64x bus card cage. The external electronic hardware is
linked to the carrier board rear access via a transition module (TRANS-200).
The electronic link from the field I/O connections to the carrier board is
made via the IP module selected for your specific application.
To facilitate easy connection of external devices to the IP field I/O pins of
the carrier board, optional Termination Panels are available. SCSI-2 cables
connect a 50 pin IP field I/O connector on the transition module (TRANS-
200) to the Termination Panel. At the Termination Panel field I/O signals are
connected to a 50 position terminal block via screw clamps. The
AVME9670A contains four IP modules, and thus 200 I/O connections are
provided via the transition module through four SCSI-2 connectors marked
A, B, C, and D.
The VME64x bus and IP module logic commons have a direct electrical
connection (i.e., they are not electrically isolated). However, the field I/O
connections can be isolated from the VME64x bus if an IP module that
provides this isolation (between the logic and field side) is utilized. A wide
variety of IP modules are currently available (from Acromag and other
vendors) that allow interface to many external devices for both digital and
analog I/O applications.
4.2 VME64x bus Interface
The carrier board’s VME64x bus interface is used to program and monitor
the carri
er board’s registers for configuration and control of the board’s
documented modes of operation (see section 3). In addition, the VME64x
bus interface is also used to communicate with and control external devices
that are connected to an IP module’s field
I/O signals (assuming an IP
module is present on the carrier board).
The VME64x
bus interface is implemented in the logic of the carrier board’s
Field Programmable Gate-Array (FPGA). The FPGA implements VME64x bus