[Info-vax] USB/DB9 terminal converter for RX2660

[Jan-Erik Soderholm]

Den 2016-06-04 kl. 02:57, skrev Stephen Hoffman:
> On 2016-06-04 00:30:26 +0000, Jan-Erik Soderholm said:
>
>> Was that in the BaseStar time frame?
>
> At least some of what John was using wasn't BASEstar.
>
> PLCs were and probably sometimes still are rather demented devices,
> unfortunately.   The old serial protocols that were common with PLCs from
> the 1980s into the 1990s (and that undoubtedly still lurk at some sites)
> were often staggeringly bad protocol designs and equally bad
> implementations, as were some of the early Ethernet protocols.   MAP and
> TOP helped (and variously hindered) with the way PLC vendors were thinking
> about these areas, but things have moved on substantially since then.
> Most PLCs and PLC software from that era tends to be prime fodder for
> Stuxnet or Irongate or such, too.  Some of what I'm familiar with was wide
> open to these and other sorts of shenanigans, unfortunately — more than a
> little of that old software was DECnet-based too, and — in this era —
> that's just as bad as using telnet.

Telnet might be bad, I don't know. We never have used telnet for PLCs.

We simply open a "raw" socket and make up some simple message protocol.
PLC sends a serial number of the product processed and the VMS application
sends an ACK back to the PLC efter storing in the database (or whatever).

I know that each PLC manufaturer (we have 2-3 different on the floor) has
it's own solution, Mitsubishu has MELSEC, Siemens has S7 and PROFINET
and so on. But it was easier to just make up a simple in-house protocol.




>
>> My point is that most sites benfits to hook up their concoles for network
>> access.
>
> For this thread, that'd usually via iLO, DRAC or other such when discussing
> servers, if the sites are not using very old hardware.  Preferably with
> access via TLS, ssh or SNMPv3, and not via telnet, LAT nor SNMPv2, etc.
>

Yes, modern servers has modern inerfaces, of course... :-)