Typical Machine Wiring 

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Typical RS-232 Wiring

The following diagrams depict the cable wiring between a DNC workstation's communications ports (either the standard built in COM1 and COM 2 or Rocketport expansion ports) and most CNC's. The numbers given are for standard 25 pin D-subminiature RS-232 connectors. On the PC side the connector must be a socket. On the CNC side it varies. FANUC and Yasnac's, for example require plugs. Okuma's and Cincinatti's generally require sockets.

If you are going to use the standard COM 1 and/or COM 2 ports that happen to be 9 pin plugs, we recommend using a 9 to 25 pin adapter so that all of your cabling can be alike and that they can be more easily serviced when a data tester (break out box ) is required for debugging. We have, however, included wiring instructions for both 25 and 9 pin styles.

What kind of cable to use

In any factory environment shielded cables are essential.  We recommend shielded cables designed for RS-232 communications.  It is 24 AWG (American Wire Gauge) and designated as "Low capacitance computer cable."   Sometimes you need only three conductors but other times you might need 5.  If there is ever a need to use RS-422 communications, such as, cable runs greater that 300' or very electrically noisy environment each signal requires a pair of wires.   Therefore, we recommend using the following:

Overall foil shielded, 3 twisted pair, 24 AWG, stranded, low capacitance computer cable. We use Carol CO901 or Belden 1420A.

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Using DB25 connectors both ends

This wiring assumes the following:
At the PC and the CNC pins 2 and 4 are outputs. Pins 3 and 5 are inputs. Pin 7 is logic ground.

PC (25 Pin socket) CNC (25 Pin-as required)
2 3 RXD
3 2 TXD
4 5 CTS
5 4 RTS
7 7 GND
  6

Jumper pin 6 to pin 8 to pin 20.  
  8
  20
Note! In general jumpering pins 6 to 20 together will suffice. For Fanuc CNC's jumpering all 3 pins is required.
   

 

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Using DB9 connector at the P.C. and DB25 at the CNC
This wiring assumes the following:
At the PC pins 3 and 7 are outputs. Pin 5 is logic ground.   Pins 2 and 8 are inputs.

At the CNC pins 2 and 4 are outputs. Pin 7 is logic ground.  Pins 3 and 5 are inputs.
PC (25 Pin socket) CNC (25 Pin-as required)
3 3 RXD
2 2 TXD
7 5 CTS
8 4 RTS
5 7 GND
  6

Jumper pin 6 to pin 8 to pin 20.  
  8
  20
Note! In general jumpering pins 6 to 20 together will suffice. For Fanuc CNC's jumpering all 3 pins is required.
   

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Notes!

Connect the shield on the P.C. side to the chassis of the PC or Rocketport adapter.  This is easily done if you use a metal or metallized plastic connector cover (hood) and make sure that the drain wire (thats an extra wire in a foil shielded cable that is connected to the foil) or the braid of a braided type shielded cable makes contact with the connector cover.

Typical parameter settings on the DNC side are as follows:

Protocol: Generic RS-232
Data rate: 9600 baud (CNC dependent )
Data type: ASCII
Parity: Even
Stop bits: One
Handshaking: If Fanuc or Yasnac like CNC's, use "Both no wait". the RTS signal from the CNC goes on at the beginning of any data transfer, and off at the completion.  If not, you must choose the handshaking method depending upon the CNC. For example, "XON/XOFF wait" is normally used with controllers that emulate EIA RS-491 level II, whereas RTS/CTS is used with level 1.

 

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BTR wiring

The DNC Control connector(J2) of the BTR motherboard combines several functions:

  1. Fault tolerant RS-232 communications between the BTR and the DNC P.C. 
  2. An RS-232 input for uploading part program files from machine tool controllers that have serial output ports.
  3. An RS-232 output for monitoring what is going out the parallel paper tape emulation port or for fault tolerant Serial-Serial communications or for certain controller that have unusual serial tape reader inputs.
  4. Connections for external Reset, Rewind, BTR/PTR switches and the I/O LED signal light.
     
 

 

CCI Fault Tolerant BTR wiring
Using DB25 connectors both ends

This wiring assumes the following:
At the P.C. pins 2 and 4 are outputs. Pins 3 and 5 are inputs. Pin 7 is logic ground.

PC (25 Pin socket) BTR J2 (25 Pin plug)
2 TXD

15 From DNC
3 RXD

17 To DNC
5 CTS

14 Ready
7 Signal Ground

16 GND
The following two signals are for the option to upload from CNC's that require a BTR for input but have a serial output (punch) port

RS-232 punch port

2 RS-232_IN
Signal Ground 7 GND
The following two signals are optionally used to monitor the data flowing into the N/C or CNC.  It can be connected to a "dumb terminal" or fed back to a "terminal emulation" window on a P.C.

RS-232 monitor port

3 RS-232_OUT
Signal Ground 7 GND
The following signals are for optional remote switches and LED indicator
SPST Toggle switch 1 8 DNC/PTR
SPST Toggle switch 2 22 GND
Pushbutton switch n/o 9 Rewind
Pushbutton switch n/o 21 Reset
Switch common 18 GND
LED cathode 10 Run signal
LED anode 23 +5 volts
 


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