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Go to our I232 page for
information on RS232 to RS232 isolation at high baud rates and long cable length.
Key Features of the Betatronics® E232 System:
- Simple procedures, ease of use, fast data transfer, and
long filenames helps in lean manufacturing and cost
reduction.
- Fast CNC program transfer, up to 1 megabyte per 90 seconds,
and over long distances (328 ft copper & a mile by fiber).
- Automatic filename generation saves a tremendous amount
of time, minimizes errors, and enhances program
management.
- Virtually impossible to overwrite an existing file on the
Central Storage Computer by a send from CNC to Computer.
- Network your RS232 CNC Machines via Ethernet to a Central
Storage Computer.
- Direct communication between Computer and CNC RS-232.
- Each CNC RS232 is run at it's maximum baud rate.
This means shortest time to transfer programs.
- DC isolation of RS232 from Ethernet eliminates ground
loops and reduces likelyhood of equipment damage from
lightning, etc.
- RS232 parameters are setup only once for each CNC.
- No manual selector switch boxes to select machines.
- Ideal for Central Computers that have an Ethernet port
but no RS-232. Most new laptops lack RS-232.
- In either direction, to or from CNC, quickly send many files.
At high baud rates 1 to 2 seconds per program for short progs.
- Organize program storage any way you want.
- Single keystroke sending of a group of programs.
- Collect cycle timing information.
Questions to Consider:
- Do you run a job or production shop with constantly changing programs
in your CNC or NC machines?
- Do you tweak your programs on the CNC, then need timing information?
- Should you backup programs but do not because of the time involved
to do so?
A tweaked program or one generated on the CNC should be saved.
- Is program loading and saving a bottleneck?
- Do you want simple and easy procedures?
- How long would it take you to transfer 100 short programs to
computer memory?
- Do you want centralized storage of your CNC programs with direct
connection to your CNC machines to avoid errors resulting from
using floppies or other loose media with outdated data, and/or
floppy drives that do not work correctly?
- Do you need to log timing information from your machines?
- Do you need machine monitoring system(MMS)capability?
Other Items:
- Near the end of this web page --- see Other Programs and Products.
- If you have sufficient memory and your browser is appropriately
set, then once these pages have been loaded you can switch
between them quickly.
- Our site checkout is done with Internet Explorer 5.5 and 6.0, and
Netscape 4.7 and 7.1. Internet Explorer produces the better results.
General Comments.
If you have a CNC machine, then you currently have some system to load and
dump CNC programs.
The system might be as simple as a pencil and paper
and you manually enter or transcribe the program. Not very efficient
or free of errors, especially on any program that is not extremely small.
At a basic RS232 level you might carry a laptop to the CNC, or use a manual
selector switch box to route the signal to a machine. This has a problem
with baud rate and cable length. The higher the baud rate the shorter the
useable cable length. Three to six feet at 115.2 kbaud. So to use a laptop at the
machine at 115.2 kbaud you need the computer very near the machine RS232
connector. Not very easy or convenient. Allowed cable length is roughly
inversely proportional to baud
rate up to some moderately short maximum length.
To put a direct Ethernet connection in your CNC may be a very expensive
option, and may not have system management features of our E232 system.
Our E232 System may be able to transfer many small programs faster than
a direct Ethernet system. The E232 system is both hardware and CNC communication software.
To use floppies is a byte limit problem (1.4 megabytes). Also a system management
problem.
In your current system ---
How long would it take to send 100 short CNC programs from your CNC to backup storage?
Same question but in the opposite direction, from storage to CNC?
How long to transfer a 5 megabyte program?
By comparsion our E232 system provides high baud rates at moderately
long distances, 115.2 kbaud up to 328 feet with no repeaters and
copper wire, and over a mile with fiber optic cable. We provide other
system mangement functions not provided with other systems.
Carefully compare our features with whatever system you currently use to
see what improvements our E232 System could provide.
The E232 System goal is Simplicity, Ease of Use, and Speed.
We want to save you time, therefore reduce costs, and provide a simple
procedure to perform
the necessary communication functions. The E232 system provides help to
manage CNC files (programs) on your central computer and CNC machines.
The overall system is an RS232 CNC Ethernet communication network.
To send or receive CNC programs requires very few keystrokes, and very
little time.
This system provides a moderately high speed transfer of CNC programs
to or from a central computer (server) to the RS-232 serial input on
your CNC machine. Different kinds of machines can be on the same network
(net). Thus, both HAAS and Fanuc Control type machines could be on the
same network and be communicated to with the same software.
An internal Ethernet connection in your CNC is not used and not required,
rather we connect thru the RS-232 port.
Communications in both directions, CNC - RS232 - Ethernet - PC, or PC - Ethernet -
RSS232 - CNC,
is provided.
Individual machines are identified by a 3 digit number in the range
101 to 250. There is no inherent limit of 150 machines, it is simply
an arbitrary value for the present. Each machine is identified by an
absolute IP address where the last three digits are the machine number.
When sending CNC programs from the CNC to the central computer the
need to type a filename at the central computer for each program received
from the CNC is eliminated. This tremendous time saver is a result of
our semi-automatic generation of the received filename. It is almost
impossible to overwrite a previous identical file.
Thus, you are more likely to backup programs on your machines because
of the greatly reduced time to do so.
Up to 115.2 kbaud transmission speed.
Data can be sent at high rates, up to 115.2 kbaud, over long
distances. Usually your CNC machine RS232 is the determining factor
for baud rate. On the Ethernet side of the system the CAT-5
cable limit is 100 meters (328 ft), and for fiber optic cable
the distance is much greater, about 2000 meters. The thruput
on the Ethernet side is vastly higher than on the RS232 side.
The Ethernet side can transfer 10 or 100 megabits/sec on a 10/100
base system over this 100 meter cable. This is 100 to
1000 times faster than 115.2 kbaud.
As an illustration of the speed of saving programs from a CNC to a
central computer we used a HAAS lathe with 110 programs totaling 147
kilobytes to run an experiment at 115.2 kilobaud. Most of the programs
were 1 to 4 kilobytes. It took 2 minutes and 33 seconds to save the
110 programs individually, and useful filenames were generated. Using
conventional techniques this would take many hours. The HAAS "send all"
of these same programs was 13 seconds. The difference between 13 seconds
and the 2 minutes and 33 seconds is operator response time and button
pushing for 110 programs. Note 147 kbytes in 13 seconds is 1.5 minutes
per megabyte.
High baud rates, up to 115.2 kilobaud, are possible with the E232 Box
because it is located at the CNC machine and only a short (three foot)
RS-232 cable is used. Generally an RS-232 connection will fail at about
6 feet (2 meters) at 115.2 kilobaud. Low capacitance cable increases the
distance. Typically the standard Ethernet
CAT-5 cable part of the system specifies and allows 100 meters (note
that experimentally we see total failure of Ethernet CAT-5 communication
at about 150 meters of average quality cable without repeaters). Thus,
all machines
must be within a 100 meter radius from their Ethernet switch. Two machines
could be 200 meters apart if the switch was centered between the two.
Additional switches allow machines to be spaced farther apart.
Switches can be located up to 100 meters between each other with CAT-5
for up to about 4 switches. Longer spacing between switches if fiber
optic cable is used. Note, 100 meters equals 328 feet.
Simplicity of Sending and Receiving files with HAAS.
When sending files (CNC programs) to a HAAS CNC with the E232 System
it is not necessary
to reset the CNC to receive mode for each file sent. You simply
use ALL RECV. Once sending is initiated at the central computer
you simply pick files in Windows Explorer to send the files.
When all files have been sent you do a termination
function. The different CNC programs can be in different subdirectories
(folders). All programs sent to the CNC must include an O number.
For older HAAS machines this can only contain 4 digits.
When sending programs from HAAS you simply initiate receive at the
central computer, then pick one program at a time at HAAS and push SEND,
or select HAAS ALL and push SEND once. At the end you quit the receive
function. As mentioned previously the filenames are semi-automatically
generated. Also in the process the filenames are made unique so that
you can not overwrite a previous similar file. Furthermore the filenames are
long allowing greater information within the filename.
Hardware and Software Components of the E232 System.
The Betatronics® E232 System Ethernet CNC RS232 consists of hardware and software
to provide a simple means to send and receive CNC programs between
a CNC machine RS-232 port, and a Personal Computer (PC) using
10/100 BASE-T Ethernet for communication, one or more standard
Ethernet switches, CAT-5 Ethernet cables, and a Betatronics®
Ethernet to RS-232 box at each CNC machine. This can be done
at the highest baud rate of the CNC up to 115.2 kilobaud, and
long distances over the Ethernet. The E232 System is essentially
a CNC communication program.
This system is designed around HAAS and Mori-Seiki (Fanuc),
RS-232, Ethernet, CNC, and should be run on XP Pro.
You can mix HAAS and Fanuc controls on the same network and
our program will communicate with either one or both or others
that are compatible.
The RS-232 interface uses 7 data bits, 1 stop bit, Even parity, and
RTS/CTS hardware handshake. The baud rate is selectable from 50 baud
to 115.2 kilobaud at standard values. However, 4800 baud probably would
be the lowest you might use. The 7 data bits corresponds to 10 bits
in the asynchronous serial signal, or at 115.2 kbaud this is 11.5 kbytes/second.
This consists of 1 start, 7 data, 1 parity, and 1 stop bit, total equals
10. If you were to use 8 data bits your thruput would drop about 10%.
Eight bits are not needed so 7 bits are optimum. Note: we prefer thru to
through and thruput to throughput because these are simpler
We have had a request for "Fanuc RS232 Cable Diagram". See E232_PHOTO page.
We use a 3 foot cable for the E232 to CNC RS-232 connection and this will work
reliably at 115.2 kbaud.
Roughly cable length is inversely proportional to baud rate. Thus, at
4800 baud you should
be able to work at about 72 feet with unshielded cable. You may be able to use
longer lengths, but this
gives you a ball park figure of a reasonable length. For short lengths, 100 ft at
at RS-232 baud rates, it is primarily a cable capacitance problem. As the load
capacitance increases the baud rate has to decrease. But, at any length
over 3 to 6 feet you should use shielded and twisted cable.
Shielding adds to the cable capacitance and thus shortens the useable cable length
for a given baud rate.
Thus, the above 72 ft probably has to be cut in half for shielded cable.
Long cables
need to be treated as transmission lines, these you might encounter in an RS-485 system.
Whereas short cables are viewed as a lumped RC circuit.
At 3 feet
we don't use twisted pairs. The purpose of twisted pair cables is to reduce inductive pickup.
Each individual signal
wire should be twisted with its own ground wire. Low capacitance cable allows longer cables.
Note: It is very easy to setup parameters and do send and receive with HAAS.
It is much more
difficult with FANUC. However, HAAS does not keep its RTS (pin 4) low when
it is not in receive
or send mode. Thus HAAS must be put into RECV before you start sending data.
The Ethernet cable is magnetically (transformer) isolated from the RS232 common (pin 5)
in our E232 box.
This means there is no dc path between the Ethernet cabling and the CNC RS232
common. This reduces grounding and ground loop problems.
E232 System Operation.
When you send and receive CNC programs with the Betatronics® E232 system
there is no concern about the baud rate and other serial parameters,
because these are preset once in each E232 Box. One machine can be 4800
baud and another at 115.2 kbaud. This has no effect at the personal
computer other than the time to transfer a given size file. Further,
you set the serial parameters in your CNC and they remain fixed.
This Betatronics® system works with one or more Betatronics®
E232 Boxes
(the E232 boxes and software are our unique components to the system).
For efficient operation one E232 Box is required at each CNC machine.
Normally we would supply only the software and E232 boxes, and you would
use whatever you wanted for the other Ethernet components.
The Betatronics® software in the PC and E232 Box are designed to work
together.
We are often asked about DNC ("drip mode"). If this is really important to you, then tell us
your needs. This type of application should have its own dedicated computer
probably running a very robust operating system, like Free BSD (few
crashes over weeks or months).
If desired, you may use a portable computer connected to the Ethernet on
the shop floor to control the sending and receiving of CNC programs.
This does not change the fact that all the CNC programs are stored
in the central computer and
are transferred over the Ethernet between the central computer and CNC.
Single Keystroke Sending of a Group of Programs.
For production applications where a number of CNC programs are associated
with a particular part (classified as a "Group of Programs")
we have a simple single operation procedure for sending this
group. This group method can reduce errors and setup time where
the same part is batch run many times. Further, it can provide
a means to document what programs were used at a given time,
and this could be valuable under recall conditions.
Time Logging Your CNC Machine Cycle (Cycle Timing).
Thru the E232 CNC RS-232 Ethernet system you can collect and time log
information from your CNC
cycle. Also tool load could be output if available. Currently the HAAS
tool load internal information is not very useful. The log time
information can be valuable for program development, production
monitoring, and problem solving (troubleshooting). But primarily
the E232 system would be used for collection over a few
cycles, 1 to 100, for detailed analysis of a particular part.
For overall continuous analysis of
many machines in an area, to collect part to part time, machine
cutting time, starved and blocked conditions, and maybe some other
inputs, then our TIMELOG system
below is more appropriate.
To do this with E232 and your CNC you will need ---
An internal timer ( In HAAS this is #3001 ).
A means to output this value to the Betatronics®
E232. In HAAS this is DPRNT in macros. With HAAS macros is an option.
A sample output might look like the following (from a HAAS mill):
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