I have a Acramatic 850 control that refuses to communicate via serial port that I have been called in to look at.
Cable between PC and machine is tested and is good. Running a full handshake cable which we can get perfect communications on between a laptop and the desktop PC intended to communicate with this CNC.
I ran continuity checks on the cable running inside the machine between the processor boards HD-15 connector and the external DB-25 connector in case it was shorted out or broken and this wire is fine.
When I boot up the CNC an alphabet series spits out to the PC "ABCDEFGHIJKLMNOPQRSTUVWXYZ" in 9600-7-n-1 com.
I am able to easily edit the COM settings in machine setup and I have tried using the default 9600-7-n-1 protocol level 1 and 2 (hardware or Xon-Xoff handshake)
That's it though. No communications once the controller boots up.
going into terminal emulation on the control and no characters come in.
Trying to do a transfer to the Line and not a single ascii character comes through on the serial port of the PC. (I have a utility that shows every bit sent or received on the computer and lets me send any ASCII code)
Tried sending a NULL (hex 00) when initiating a file transfer and no response until the controller times out.
I'm wondering if the machine somehow got switched to RS-423 mode as it appears from the documentation that the DAMP processor board on this control can be set for either RS-232 standard serial or RS-423 serial. It refers me to "For additional information refer to DATA LINE MANUAL 7-000-0690AN" which seems to be the only documentation I do not have for this machine. Otherwise it seems like they have a complete set of manuals for the machine and the controller which is rare for a machine of this vintage. (1994)
Anyone know more about the specifics of Acramatic 850sx control settings?
Anyone know what the 4 service switches on the DAMP card do and what position they would normally be in?
Any jumpers on the DAMP board if I removed it from the backplane that would apply to this situation?
I'm missing some secret here and before I start to suspect a bad DAMP board and go calling Siemens or searching for used parts I want to make sure it's not just a setting somewhere or some magic ascii string needs to be sent from the DNC software to communicate.
The machine used to communicate I'm told but I'm also told the former operator and only guy who knew how it worked quit and "took the cable with him". Now I'm totally confused by this statement. Why anyone would care about a cable unless it was an RS-423 converter I fail to see why there would be anything special going on there.
If I had an RS-423 converter I would probably be hooking that up to see if it's stuck in this alternate cabling mode. As fate would have it I threw out an old RS-485 converter I had which was missing a power supply recently though I'm not sure it's the same thing as RS-423 anyhow. RS-422, RS-423, RS-485 all seem to be slightly different differential / multi-drop serial protocols and I'm not too sure they are compatible in any way shape or form. The manual I have at least lists the RS-423 pinout on the aux connector of the DAMP board which is something if I need to travel that route.
Goofy serial guru needed. Thanks.
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