In order to connect output ports, commands are sent to the CAS-41A via the Control Port. As
mentioned previously, each command consists of two components; the Prefix Code (see
Section 3) and the Instruction Code. This Section describes the procedure for using Instruction
Codes to select the CAS-41A's sixteen possible port combinations.
4.1. Port Selection
The Instruction Code follows the Prefix Code and tells the CAS-41A to connect one or more of
the unit's four output ports.
The chart on the following page describes 64 possible Instruction Codes that can be used to
select sixteen possible port combinations. Note that each port combination can be selected by
any of the four characters listed for that combination. For example, in order to connect Port 1,
the Instruction code could be !, 1, A, or Q.
When sending commands to the CAS-41A, note the following:
·The Prefix Code selected by the current Code Setup Switch configuration must be sent
before each Instruction Code.
·Bits 1, 2, 3 and 4 of the Instruction Code correspond to output ports 1, 2, 3 and 4.
·The Instruction Code is not sent out through the ports.
·The next character received after the Instruction Code is sent out through the selected
·Non-printable characters cannot be used as Instruction Codes.
Connected Ports Possible Instruction