dbx quick_guide - Manual

Controlling DriveRack™ products with RS-232: A quick start guide.
If you are using an AMX panel with a NetLinx control module, you are in luck. There is
NetLinx sample code available for the DriveRack 400 series processors. This code can
be used as a template to create your application. The 200 series and 400 series us the
same message format, and share all of the most often used messages. Adapting the
sample code to control a 240 or a 260 should be an easy task.
If you are not using an AMX NetLinx control module, you will need to perform a little
more programming on your chosen controller.
There are two modes of sending messages. Guaranteed Delivery and Data Gram. The
full handshake protocol for resynch and guaranteed delivery is described in a separate
document. A full implementation of the protocol is recommended to provide fault
tolerant communication with Drive Rack products. Generating and responding to
Resynch Requests, acknowledging received guaranteed frames and resending frames that
have not been acknowledged will provide a control interface that is robust. You will not
have to tell your customer “if it didn’t work, just hit the control button again to resend the
command….”.
Many times, however, a simple open loop message system is adequate for the application.
This quick start guide will allow you to control some common parameters in the
DriveRack series of products using the “canned” strings provided below. This guide is
not intended to replace the “Full Duplex Network and Data Link Layer
Specification”, but is intended to help send a few commands to a DriveRack to get
started working on a control application.
Baud Rate: 38.4 kbps, 8N1
Reysnc:
Whenever the controller begins operation, resynch to the DriveRack. This ensures that
the communications protocol is flushed and ready to receive a message frame.
First send 16 <0xff> characters to the DriveRack.
Then send 261 <0xf0> characters to the DriveRack.
Now as long as the controller sends valid frames, the controller and DriveRack will stay
in Synch.
Ping:
If a ping is received <0x8c>, send a ping back <0x8c>.
The Message Frame:
The commands to the frame is an SDLC packet frame. The packet frame for a Data
Gram is as follows.