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de003

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  1. What you say follows what is in the manual in essence. I am confused by the below image which seems to contradict what you're saying. I have seen various versions of this graphic in several places. I'm not saying you, or it, are wrong... but my confusion is that it doesn't seem possible for both to be correct!! In the below drawing, it seems that where the driver (in this case a momentary switch) pushes current into the load (PLC input), that is referred to as a sinking input. This is where I'm confused.
  2. Hi all I am relatively new to PLC programming and using a Samba 35 to teach myself. I am familiar with the relevant principles but I am being a touch confused by how PNP and NPN wiring are visualised in the manual. For reference I am looking at the manual at https://www.unitronicsplc.com/wp-content/uploads/2015/12/SMXX-J-T20_R20_DOC17015-A4_02-15.pdf , pages 7 & 8. The manual as linked above, seems to suggest that a + common is NPN and a - common is PNP. But every other resource I've read (for example, http://plchowto.com/wiring-plcs/ ) describes them as the opposite. I have been used to the idea that for NPN, the switch or sensor goes between the 24VDC supply and the PLC input; whereas for PNP, the switch or sensor goes between the Common and the PLC input. I'm a bit confused... the manual seems to contradict everything else. Can anyone clarify this for me? Thanks
  3. Just to report - with thanks to everyone involved - with the Unitronics programming cable it works fine.
  4. That's a very valid point. I think the unfortunate downside is that so few computers are shipping with anything other than USB for serial ports. In my last job I had to manage servers which outputted RS485 for motion control from USB cards (made in-house). It was really important to keep the server off the internet when connecting hardware for that exact reason, Windows would try and download some 'closest thing I can find' driver from the internet, replacing the manually installed actual driver automatically. Oh don't worry I've done my fair share of paper manuals... a lot of my job is repairing and revitalising very old, obsolete systems which may or may not be provided with documentation. That'll often be a case of meeting a 'technical manager' who's far from technical, and him scratching his chin for 5 minutes before bringing me a pile of lever-arch folders full of disorganised print-outs with an inch of dust collected on top, which the installer provided with the system in 1995 and have been kept 'just in case we ever need them'. ...
  5. This is annoyingly not alluded to anywhere on the product website or in the manual... So after all the chat, I found one on eBay for $5 and bought it Thanks for the pointer towards the Visilogic manual. I ought to know better than to expect automation manufacturers to have user friendly websites.
  6. Yep that certainly does help, since bizarrely they don't include that table in the Samba manual (only a more basic pin-out). That said, I have no real way of wiring both pins 2 and 5 on the RJ11, to pin 5 of the DB9. I don't suppose you happen to know if there's an alternative pin I can wire to, to achieve ground?
  7. Whilst I'm confident of the USB-RS232, I did have a closer look at the DB9 - RJ11 cable and I'm not convinced the wiring is right. I've ordered some different bits from RS and will have a play with those before whining further! In my experience, 90% of automation faults are cable not plugged in, cable broken or something needs a power cycle... Sadly Joe, whilst I appreciate your support, you are mistaken. It seems a USB connection is offered on every Samba and Vision PLC except the SM35! Trust me - had it had a USB connection, I wouldn't have gone down the RS232 route in the first place... Gonna have a play with cables as above, thanks for the ideas anyway, I'll come back if it's still no bueno...
  8. Hi All. I have recently bought a Samba 35-J-R20 for a small project. I am new to Unitronics. I cannot get VisiLogic and the PLC to talk - I'm getting the same 206 comms error as above. This is in a new, blank file - just trying to get comms between VisiLogic and the PLC. I'm using a USB-DB9 RS232 adaptor, and a DB9-RJ11 cable jumper. In Device Manager, in VisiLogic, and on the PLC (Info Mode) I have the same comms settings - COM Port 1 (Serial), Baud rate 57600. It offers me four potential causes: 1. Cable connections not secure (checked - they are) 2. Timeout is too short - it's set to 1s... I tried it at 10s out of principle, and no change. 3. Incorrect communication settings (see above) 4. Current user name is not authorised for this action: I have not logged in to anything so I don't know where to check this... I haven't got the means at home to go testing cables. Can I just ask if I've forgotten to check anything simple before I start blaming hardware?
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