Reply with QuoteSome years ago I ended up taking a Fanuc tape reader and designing my own tape-to-ASCII conversion, in order to read the data in using RS232.
I used a large Intersil UART IC IM6402, IIRC.
Paper Tape Reader Interface Documentation
I'm working on interfacing a Paper Tape Reader, specifically a Fanuc A13B-0070-B001, to a computer - at hardware level a Xilinx Zynq via a CPLD.
This is a retro computing project with the objective of reading 1" paper tape. Initially using the Zynq's FPGA fabric and Arm Cortex A-9, with the potential to interface to an (FPGA) PDP-11 (or 8) implemented in the Zynq.
There appears to be little documentation of the tape reader interface generally and specifically of Fanuc PCBs; a schematic for the tape reader electronics (Fanuc A20B-0007-0750-07B) would provide 90% of what I seek.
The interface is of course that employed by a Fanuc BTR. However, it is applied to the much less common tape reader use case. And, I can't find a BTR Fanuc Tape Reader interface specification.
Initial reverse engineering has identified the likely basics of the 50 way parallel interface (using Fanuc's pin out nomenclature):
B 1 .. 24 Gnd
B25 n/c (pin out as key)
A 1 .. 8 Reader channels 1 .. 8, i.e. bits 0 .. 7 [5v TTL]
A 9 Sprocket channel [5v TTL]
A 10 / 12 / 20 to 5V pu thro 220R : function ?
A 11 / 13 driven outputs [5v TTL], function tbd
A 21 / 22 5V supply
A 23 / 24 24V supply
A others n/c ?
Specific questions:
- 24V is the correct Fanuc Tape Reader supply voltage for electromagnet actuation etc ?
- BTR / tape reader interface specification
- Fanuc documentation for Tape Readers, below the CNC system maintenance manual level (e.g. B-52245E/04 https://www.vintagecomputer.net/fanu...anuals1788.pdf)
- Generic functions of pins A 10 11 12 13 20
- What is the specification of the (unused ?) 6 pin x 0.2" pitch Burndy DC supply connector and are mating halves available; from the machining dust I doubt it was used in the readers previous life
All / any information, advice, wisdom will be gratefully received
OldFellow
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Re: Paper Tape Reader Interface Documentation
Some years ago I ended up taking a Fanuc tape reader and designing my own tape-to-ASCII conversion, in order to read the data in using RS232.
I used a large Intersil UART IC IM6402, IIRC.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: Paper Tape Reader Interface Documentation
Al,
Thanks for confirming that it's been done before; you would not have any notes on (in particular) the Fanuc 50 way interface ?
The main issue is what status / control lines pass through the 50 way interface.
I doubt this will interface to a UART, in the SoC/FPGA fabric its more likely to travel bit parallel like a DEC PC01 / PC11 combination.
Re: Paper Tape Reader Interface Documentation
I did not use the interface board shown, I took the 8 Bit read head output directly into the the UART circuit.
The sprocket hole is read also and used for clocking the 8 bit data.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: Paper Tape Reader Interface Documentation
Al,
Thanks again for your comments
My main takeaway is that Fanuc's fussing over the comparator threshold levels is of marginal consequence - I guess you went into regular TTL or at best Schmidtt trigger inputs
It serves my purposes to use the interface as it (should) look after the electromagents and possibly offer slightly more value, therefore digging into the logic
I fully apreciate that the 8 bits and sprocket essentially pass through the interface, and that the narrow sprocket hole provides implicit edge transitions for sampling the data stream
The plan is first order understanding, basic break out card (to provide supplies), observe behaviour with CRO, DMM and Mk I eyeball, refine interface, repeat
Re: Paper Tape Reader Interface Documentation
An update on progress and some unresolved questions.
The attached image shows a parallel interface through an (ADC EVB) adapter board to a Digilent Zybo / Xilinx Zynq.
The interface is zenners, knitting, a byte wide FIFO and thence the Zynq's AXI bus via data and CSR registers.
Sprockets falling, trialing edge clocks the data into the fifo, the switch in auto position asserts A11 which both engages the pinch roller and gates "valid" data.; data quality seems good.
Pins 10, 12 and 20 are simply pulled up by the interface.
Unresolved questions:
- what is the purpose, effect, use case of the input (to the tape reader) signal on A13 ?
- what is the intended functionality of the front panel switch's Auto and Manual positions (an operating question) ?
- and some of the questions from my original post
The brief summary is it reads paper tape into a computer, the data looks good, I have a moderate understanding of the Fanuc electronics.
And, armed with what I learned from this exercise I fixed a defective PPR reader; the illuminators constant current source was dead.
An Update
Re: Paper Tape Reader Interface Documentation
Not sure if it answers your question, but the 8th bit on the tape is the parity check bit.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: Paper Tape Reader Interface Documentation
Bit 7, the 8th bit, on CNT1 A8 can indeed be used for parity in text streams. Generally, I'm working with binary data and its just the top bit of the byte. E.g. in DEC absolute binary tapes data validity is checked by a longditudal checksum, with a final checksum byte to verify the data.
The particular input bit I was querying, CNT1 A13, heads off to an LS123 monostable on the Fanuc interface card - I wondered if anyone knew what its purpose / effect was ?
Additionally, I wondered if any of the old hands could recollect operating this kit sufficiently well to comment on how it was operated - in particular how the auto / off / manual switch was used with the other system controls - oh for an operators manual. Loading tapes and running them through in auto I'm happy with to a 1st order.
