• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Communication Between PC And Vending Machine Using PC's RS232 Using Virtual COM Port (USB) Cable And Vending Machine's Multi-Drop Bus Port (MDB) Port

BusVend

New Member
I've disconnected the MDB cable from the first MDB port (MDB1) and connected it to MDB2 on the vending machine. I contacted our vending machine supplier Benleigh Vending and they stated that the switching of connections should be automatic but I can't seem to get a reply from MDB2 when I send a signal from my PC application which is sent from an application using RS232 (USB Virtual COM Port COM7) port to the MDB port on the vending machine. I chose the MDB2 port on the vending machine as MDB1 caused issues with the vending machine operations and the PC running Windows 10 Professional. I searched for a switch on the motherboard but couldn't find one. I'm wondering what I should do?
 

narkeleptk

Active Member
Call tech support for the vending machine company is probably going to be your best chance of sucess, maybe they have some one who can team-viewer in and help you remotely.
 

Pommie

Well-Known Member
Most Helpful Member
Double check in device manager that it is actually com7. Do you get an error message from the software?

Mike.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
I think you will likely find the "MDB" connections are not RS232 (using 12V levels) but balanced line such as RS485 or RS422.

You can get USB-Serial adapters to suit those, but they are less common than basic USB COM Port type adapters.
 

Latest threads

EE World Online Articles

Loading
Top