Driver for LeCroy LT364 Scope with Ethernet interface

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Driver for LeCroy LT364 Scope with Ethernet
interface

• PENG,Sheng
• Brookhaven National Laboratory

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Driver for LeCroy LT364 Scope with Ethernet
interface

• vxWorks driver
• General Fast
• EPICS device support
• In fact, this driver could be used with almost
  all LeCory scopes with Ethernet interface

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(No Transcript)
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MEDM
Two CPU Boards
Ethernet
IOC
Share memory
LeCroy LT364
CPU Boards
Ethernet
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LeCroy LT364 Specification

• Sampling Rate per Channel500 MS/s max when
  using four channels
• ( 1 GS/s when using two channels)
• Vertical Resolution 8 bits
• Sensitivity 2 mV 10 V/div fully variable
• Clock Accuracy lt10 ppm
• Interpolator Resolution 5 ps
• Processor 160 MHz PowerPC
• Memory 16 Mbytes
• Interface 10Base-T, GPIB, Serial port
• Setup source Floppy Disk, NVMEM

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Benefit

• Fast. Normally we control scope via GPIB
  interface, Ethernet interface is faster
• Easy to use. We have Ethernet everywhere and
  length limitation of cable is much longer then
  GPIB
• Easy to port. Driver is only based on BSD 4.3
  compatible socket, so its easy to port. We dont
  need to ask manufacturer to support particular
  platform.

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Performance (general)

• We tested our driver (version 0.2), it can work
  on 60Hz ( 1000 points)
• For one IOC to Multi scopes mode
• We did a simple test to our IOC (MV2302) by ftp a
  file to RamDisk in IOC, the throughput could be
  26Mbps. For one scope ( EPICS record scan rates
  is 10HZ, and 1000 points per waveform ) we need
  101k880kbps. So I believe one IOC can support
  at least 10 scopes at same time

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Performance (fast)

• The format of response from LT364
• The head is 8 bytes. First byte indicates if its
  last block, last four byte is length of following
  data block.
• General driver reads head each time then data.
  Fast driver read fixed length
• Enlarge socket buffer is helpful
• The actual rates is up to load of scopes CPU
• In particular case I reach almost 1000Hz

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Function definition

• LT364ID open_LT364(char addr)
• STATUS close_LT364(LT364ID lt364id)
• int read_LT364(LT364ID lt364id, int chnl, float
  waveform, int pts)
• STATUS ioctl_LT364(LT364ID lt364id, int chnl, int
  op, void arg)

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Supported op

• RESET
• Not channel-related, dont need arg.
• ENABLECHAN
• Enable channel chnl, dont need arg.
• DISABLECHAN
• Disable channel chnl, dont need arg.
• GETCHANSTAT
• Get channel chnl status (ON or OFF), store to
  arg as integer.

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Supported op (cond)

• SETMEMSIZE
• Not channel-related, set waveform length. arg
  should point to an integer.
• arg length arg length
• 0 500 1 1K
• 2 2.5K 3 5K
• 4 10K 5 25K
• 6 50K 7 100K
• 8 250K 9 500K
• 10 1M 11 2.5M
• 12 5M 13 10M
• Sample rates memsize/(timediv10)
• Which is longest one for you scope is up to how
  much memory your scope has.

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Supported op (cond)

• GETMEMSIZE
• Not channel-related, get waveform length and
  store to arg as integer.
• SETTIMEDIV
• Not channel-related, set time div. arg should
  point to a float. Unit is second.
• GETTIMEDIV
• Not channel-related, get time div and store to
  arg as float. Unit is second.

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Supported op (cond)

• SETVOLTDIV
• Channel-related, set Volt div of channel chnl.
  arg should point to a float. Unit is volt.
• GETVOLTDIV
• Channel-related, get Volt div of channel chnl
  and store to arg as float. Unit is volt.
• SETTRGMODE
• Not channel-related, set trigger mode. arg
  should point to a integer. arg means
• 0 AUTO 1NORMAL 2 SINGLE 3 STOP
• GETTRGMODE
• Not channel-related, get trigger mode and store
  to arg as integer.

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Supported op (cond)

• SETTRGSRC
• Not channel-related, set trigger source. arg
  should point to a integer. arg means
• 0 Ext 1C1 2 C2 3 C3 4 C4
• GETTRGSRC
• Not channel-related, get trigger source and
  store to arg as integer.

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Supported op (cond)

• LDPNLSTP
• Not channel-related, load panel_setup from nvmem
  in scope. arg should point a integer.
• arg means nvmem number(0-4). arg equal 0 means
  load default panel_setup.
• SVPNLSTP
• Not channel-related, save panel_setup to nvmem
  in scope. arg should point to a integer. arg
  means nvmem number(1-4).

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In the future

• We will upgrade our driver to support more
  functions to fit our application
• We hope LeCroy will upgrade Ethernet interface of
  LT364 from 10Base-T to 100Base-T, so we will get
  faster refresh rates.

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How to Use

• At first,you should call open_LT364.
• The parameter is IP address of your scope.And
  return is a struct pointer if successed or NULL
  if failed.
• When you finished using scope, you should call
  close_LT364 with parameter returned by open_LT364.

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How to Use (cond)

• After you call open_LT364, if you want to control
  or monitor the configuration of scope that is not
  related to a channel, you can use ioctl_LT364
  with parameter chnl equal 0. If you want to
  control or monitor the configuration of scope
  that is related to a channel, you should call
  ioctl_LT364 with chnl as what you want and op as
  ENABLECHAN first.

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How to Use (cond)

• If you want to get waveform, you should prepare
  an float array with correct length.Then call
  read_LT364 with chnl as which you want to read
  and pts as how many points you want. And you can
  get exact waveform length by call ioctl_LT364
  with chnl equal 0 and op as GETMEMSIZE.

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How to get it

• E-mail
• peng_at_bnl.gov
• Telephone
• [phone]
• Web
• http//www.sns.bnl.gov/epics/enet-scope/