MicroVAX/VAXstation 2000 (was Re: Back from the fleamarket)

Here's a quickie from Optimized Engineering <http://www.optimized.com/COMPENDI/RS-R423.htm>: " Whereas the RS-232 standard defines a bi-directional interface between exactly two communicators, the RS-423 standard defines a uni-directional interface between one transmitter and many receivers. For example, a single computer may need to update a number of terminals that are displaying, for example, a customers order information at multiple locations throughout a warehouse. The data direction is always in one direction. RS-423 allows for distances up to 4000 feet but limits data rates to only 100 kb/sec for a maximum of ten receivers. The voltage levels are +3.6 to +6 volts to represent a binary 0 and -3.6 to -6 volts to represent a binary 1. The voltage levels are defined relative to an earth ground potential assumed to be zero volts. Consequently a difference in ground voltage levels will result in the Common Mode Voltage problem that will confuse the data values. " If you start with that, you can probably get where you need to go. This refers to some logical differences. Voltage standards overlap somewhat. Dick ----- Original Message ----- From: "Jay West" &lt;west(a)tseinc.com&gt; To: &lt;classiccmp(a)classiccmp.org&gt; Sent: Tuesday, July 03, 2001 6:56 PM Subject: Re: MicroVAX/VAXstation 2000 (was Re: Back from the fleamarket)