User guide

Chapter 5 - PASHA
52 Version 1.7.2.0 March 27, 2015
Using a PC
The serial command protocol used by PASHA is human-readable ASCII, so you can test and
debug PASHA control of a specific project using just a Windows-based PC with a spare serial
port – MediaMatrix hardware is not required. When emulating a MediaMatrix node using
NWare on a PC, the PC serial ports can simulate the PASHA behavior on the node.
Note: If you want to use RS-485/422 with your PC, it must be fitted with an RS-485/422 serial
interface card on COM1, or you need to use an interface converter device plugged into the
COM-1 RS-232 port.
PASHA user IDs and control aliases
In order to refer to NWare controls using the PASHA protocol, you need to assign a user ID to
each control. User IDs are equivalent to control aliases in the RATC protocol, except they are
limited to three alphanumeric characters.
Notes:
 Any alphanumeric character may be used, but the protocol is case-sensitive, so aaa is
different from AAA.
 Only aliases that are exactly three characters long can be used.
For information on assigning user IDs / control aliases, see Controlling NWare controls (on
page 11).
Message protocol
PASHA messages are ASCII (text) strings. While they contain hexadecimal numbers, the hex
numbers are represented by ASCII (text).
Each message begins with a message-type character and ends (with the exception of the NAK
message) with an end-of-message period character (.). Each message to PASHA results in a
response message from PASHA. PASHA never sends a message except in response to an
external message.
In general, the protocol supports setting and getting control values. The alphanumeric
characters used to identify a control are set as a control alias on the properties of the control in
NWare. Control values are specified with a 2 digit hexadecimal number, in the range 00
through FF.