Hello Joe,
It really isn't hard. You need a PC, or Laptop, preferably with a physical Serial Port (not an emulated Serial Port using a USB to Serial adapter). USB to Serial adapters can be problematical and given that this seems to be your first venture into settings up communication with a CNC control, you won't want the hassle. There are some that work better than others, and there are those that just don't work with Win7 and above Operating Systems when installed as 64 bit OS. Accordingly, if the PC, or Laptop only has USB Ports (often the case with Laptops, but Desktop PC's usually have at least one 9 pin Serial Port), and therefore you will have to spend money on either a USB to Serial converter, or a Physical Serial Adapter Card, I would opt for the Real Serial adapter every time.
When using a Software application to communicate between two devices and unless the Software is total rubbish, there is absolutely NO requirement to have to set Date Bit, Stop Bits, Parity, Baud Rate and Handshake Method through the Device Manager. All of this is set through the Comms setting of the Software application. The attached picture shows a typical RS232 protocol setting page of a Software Application used to communicate with another device.
View attachment 172321
With regards to the FIFO setting, changing this is usually only required if the particular UART of the PC can't react quickly enough to a Stop Signal sent by the receiving device, usually when using Xon Xoff Handshaking (normally DC3 - Ascii 19 character).
Software Handshaking will work fine with your Cincinnati Control and following is the pin-out of the cable your will require:
Cable Pin-out for Xon Xoff Handshaking
Machine Side --------------------------- PC Side
DB25 Male Connector --------------- DB9 Female Connector
1 --- Shield Trace ------------------- Not Connected
2 ----------------------------------------- 2
3 ----------------------------------------- 3
4
| Bridged
5
6
|
8 All Bridged
|
20
7 ----------------------------------------- 5
The confusion when purchasing a ready made cable, is that you will be told to just ask for a Null Modem Cable. The problem here is that Null Modem is a generic term and refers to any cable where the TX and TD lines in the cable are swapped. There are basically three types of Null Modem Cables and they relate to Handshaking.
1. None
2. Loop-back Handshaking (Xon Xoff)
3. Hardware Handshaking
You need a Loop-back Handshake Null Modem Cable.
I always make my own cables, as they are easy to make and I'm then sure they are correct.
The Shield Trace referred to in the above schematic is a bare wire that runs the length of the cable and is in close contact with a Shield Wrap that encloses all the wires in the cable. This Trace wire should only be connected to Protective Ground at one end of the cable (Pin 1 of a DB25 Connector - the frame of a DB9 Connector). Unless the two devices are connected to the same Ground Source and both are Grounded well, connecting the Trace wire at both end can result in a Ground Loop.
As you can see from the above cable configuration schematic, the cable is fairly simple to make. I see no reason to complicate matters by introducing adapters when the above cable can be connected directly to the machine control and the PC.
The parameters of the machine relating to RS232 Comms needs to be set and the Software being used on the PC has to have its RS232 protocol setting made compatible with the parameter settings made at the Control. The Cincinnati Control is a little different in the way it handles RS232 Comms. A Fanuc for example will use 7 Data Bits and the same is set at the External Device Software. A Cincinnati control will be set to 8 Data Bits, 1 Stop Bit and No Parity. Yet the PC Software will be set to 7 Data Bits, 1 Stop Bit and Even Parity. This is because the Cincinnati control counts the even parity bit used in Protocol 1 as a data bit.
Refer to your Cincinnati Control Manual on how to set the parameters.
The PC Software should be set as follows:
Handshake Method = Xon Xoff (Software Handshaking)
Data Bits = 7
Stop Bits = 1
Parity Pit = Even
Baud Rate = 4800 (or to whatever the Baud Rate is set in Control Parameters)
Regards,
Bill