Rockwell Automation 57C620 AutoMax Programming Executive Version 3.8 - Manual (Page 255)

HĆ1 Using Foreign Modules in an AutoMax Rack
Appendix H
Using Foreign Modules
in an AutoMax Rack
A foreign module must meet the following hardware and software requirements
before it can be used in a local or remote AutoMax rack. See the AutoMax Power
Supply Module and Racks Instruction Manual (J2Ć3008) for more information.
Hardware Requirements
1. The foreign module must conform to general IEEE 796 specifications. The
AutoMax rack will support foreign modules which meet the following level of
IEEE Standard bus compliance: D16M20I16.
2. For foreign modules that have field connections, the field connections must
be electrically isolated because the rack does not have a direct connection to
ground. See the figure below for more information.
10K Ohm
.1 m F .1 m F .1 m F .1 m F
3. The BCLK (Bus Clock) signal is activated only by the presence of the
Common Memory module (M/N 57C413 or 57C423). Consequently, if the
foreign module requires this signal, the Common Memory module must be in
slot 0 in the rack.
4. For foreign modules that can serve as bus masters, i.e., can control the bus, if
the rack already contains a Processor, the Common Memory module (M/N
57C413 or 57C423) must be in slot 0 in the rack.
5. The bus arbitration method used by AutoMax systems is parallel roundĆrobin.
Any foreign module that can serve as a bus master must support parallel
roundĆrobin bus arbitration. Bus arbitration is supported only in slots 1
through 4. Bus masters can be placed only in these slots.
6. The CCLK (Constant Clock) signal is activated only through one of the
following modules: Resolver Input module (57C411), 2ĆChannel Analog Input
module (57C409), UDC module (57552), or the Pulsetach module (57C421).
If the foreign module requires the CCLK signal, one of these modules must
be in the rack and the command to activate CCLK using the appropriate bit in
one of these modules must be issued in an application task.
7. Foreign modules must not generate interrupts.
8. For foreign modules in remote racks, inputs must respond only to Multibus
memory read. Outputs must respond to both Multibus memory read and
write. If this is not the case, the foreign module will be treated as an output
module only by the remote I/O system.