HU-PYXIS
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PYXIS
System User Guide
4.2.4 Control Protocol Options
Part of the database configures the protocol used on the RS485 ports on the rear panel. There are 4
pre-defined protocols each suitable for different device/application connections. This section
describes each protocol. Refer to the Nebula User Guide for details of configuration within the
database.
General Switcher Protocol (SW-P-02)
Multi-drop Communications Protocol (SW-P-06)
General Remote Control Protocol (SW-P-08)
Simple Switcher Protocol (SW-P-03)
4.2.4.1
Snell General Switcher Protocol (SW-P-02)
Snell General Switcher Communication Protocol is the preferred method of controlling Snell routers.
It uses numbers in the range 0 to 1023 to set, acknowledge and poll crosspoints via a single router
control module. Pyxis ports must be configured for this protocol if the router is to be controlled by an
Aurora control system
Although labeled ‘RS485’, this port is actually software configured to be point to point, as with RS422,
when using this protocol.
The full specification for this protocol is available from Snell, or on our website (www.Snell.com).
4.2.4.2
Snell General Remote Control Protocol (SW-P-08)
This protocol has been developed to provide a common method of interfacing Snell router control
systems to a variety of standard and custom applications. An example of the use of this protocol
would be the interfacing of the Pyxis system to a Soft Panel control system, or to a TSL Under
Monitor Display system. General Remote protocol allows the controlling system to access and
control all system parameters, using the database configured names, as well as level, source and
destination numbers.
The full specification for this protocol is available from Snell.
4.2.4.3 Snell
Multi-Drop Communications Protocol (SW-P-06)
This protocol is designed to communicate between a Snell router control system and router control
panels and Under Monitor Displays. Up to sixteen ‘devices’ may be ‘daisy-chained’ onto one multi-
drop control port, each device requires a unique address, identified using a rotary HEX switch. The
control system database must hold configuration data for all devices.
The full specification for this protocol is available from Snell.