A RDM Transceiver Qualification Tester 

from Goddard Design

  Your  DMX512 & RDM Test Tools Source

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Goddard Design is proud to introduce an important test tool for anyone designing or verifying a new E1.20 (RDM) design. Our RDM Driver Qualification Test Set simplifies the required driver tests.

If you are designing an RDM device, the selection of the line driver is not as simple as it once was. Just because an integrated circuit is labeled as a EIA485 driver does not mean that it is appropriate for RDM use. Electrical requirements have been added to increase the reliability of the protocol. For the purposes of E1.20 (RDM) the line transceiver IC and any bias components are jointly considered to be the line driver, and together must be qualified to drive the EIA485/E1.20 line. From the standard:
2.4 Maintaining data link state between packets
. . . Typically, there may be considerable time when all transmitters are in a high impedance state. It is imperative that the data link shall maintain a marking state between packets, even if all transmitters are disabled.” . . .
“The command port shall provide a means to bias the termination of the data link to a value of at least 245 mV and verified by using the test circuit described in Appendix F.”

Because schemes providing this bias place an additional electrical load on transmitters, all controller and responder transceiver designs must be tested for conformance. While these tests are simple, construction and verification of a  test set can be time consuming and expensive.

Goddard Design now offers a three PCB set that allows any EIA driver and biasing scheme to be tested to the requirements of Appendix F in a matter of minutes.
The test set includes:
  •  A standard test load card that implements the four required tests
  • Two DUT test cards that take a standard 485 transceiver in an 8 pin DIP package. An adapter to SO8 or SOP8 packages is available. One card comes with the E1.20 default bias network installed, the other card is left open for user designs.
  • Three universal switching powers supplies are included.
  • All the user needs to provide is one adjustable bench power supply capable of supplying the DUT, and a good quality DVM.

   Professional Net Price List
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  RDM Driver Qualification Test Set $345. #
 Adapter 8 pin DIP to SO or SOP package

For delivery within NY state add applicable sale tax.

You may a download the print version of this data sheet. (5.16M) Adobe logoThis file is in PDF format. You will need a PDF viewer to read and print it. If you do not have one it may be downloaded for free from Adobe.
Goddard Design Company
51 Nassau Ave.
Brooklyn NY 11222 USA
718 599-0170 718 599-0172 fax

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last updated April 20, 2011