ELAN DIGITAL SYSTEMS LTD. LITTLE PARK FARM ROAD, SEGENSWORTH WEST, FAREHAM, HANTS. PO15 5SJ. TEL: (44) (0)1489 579799 FAX: (44) (0)1489 577516 e-mail: support@pccard.co.uk website: http://www.pccard.co.uk USBcount50 USER’S GUIDE ES381 Important Notice: Please refer to Safety Data 4.4.1, before using this instrument All Trademarks are duly acknowledged. The USBcount50 is Patent Pending. REVISION HISTORY ISSUE PAGES DATE NOTES 1 30 27.02.2006 FIRST ISSUE Elan Digital Systems Ltd.
CONTENTS 1 OVERVIEW................................................................................................ 5 2 ABOUT THE USBCOUNT50..................................................................... 6 2.1 General ............................................................................................................ 6 2.2 USBcount50 Architecture .............................................................................. 7 2.3 Using More Than One USBcount50...........................
4.4.4 Software ................................................................................................... 30 Elan Digital Systems Ltd.
Disclaimer This document has been carefully prepared and checked. No responsibility can be assumed for inaccuracies. Elan reserves the right to make changes without prior notice to any products herein to improve functionality, reliability or other design aspects. Elan does not assume any liability for loses arising out of the use of any product described herein; neither does its use convey any license under its patent rights or the rights of others.
1 OVERVIEW The USBcount50 is an isolated digital pulse counter that has the following features: • Single channel pulse counter with BNC input and USB PC interface • Each USBcount50 can be stacked to increase channel count (each requires its own USB connection)1 • 300V Cat II isolation between BNC ground and USB ground2 This means that there is no DC path through the USBcount50 from the counters input to the PC’s ground • Up to 50MHz input counting, 100MHz with suitable input signal • 10ns timing resolution
2 ABOUT THE USBcount50 2.1 General The USBcount50 has been designed to allow a broad range of input frequencies and pulses to be measured. The input stage supply is programmable to allow the counter to work in circuits generating various Voh levels. Each USBcount50 can be used as an independent single channel counter but to enhance flexibility several USBcount50s can be stacked together to make a combined 2,3 or 4-channel device.
2.2 USBcount50 Architecture The figure below shows a simplified diagram of the USBcount50. STACK CONN INPUT PROTECTION CONTROLLER & COUNTER ` BNC USB CONTROLLER Vsupply DATA 8-BIT DAC PSU ISOLATION BARRIER Figure 2.2-1 USBcount50 Architecture Diagram Elan Digital Systems Ltd.
2.3 Using More Than One USBcount50 2.3.1 Stacked Mode A unique feature of the USBcount50 architecture is that up to 4 devices3 can be stacked to make a multi-channel instrument. In order to use a stacked configuration, you must purchase the stacking connector kit. This kit comprises 3 long lead connectors and 1 short lead connector as shown: 2.3.1.1 Assembling The Stack To stack the USBcount50 devices, first be sure that none of them are connected to a USB port.
Repeat this for all except the last counter to be stacked. For the last counter in the stack, do the same as above but use the short length connector. This time, the pins are shorter so they stop well inside the counter’s case. This counter MUST be the bottom counter in the stack.
Start with the bottom counter. Hold it in one hand, and put the next counter on top of the 1st, the same way around. Align the stacking connectors and when the stacking connectors are partly mated engage the front “P” shaped clip (BNC end) on the 2nd counter into the “P” shaped slot on the 1st counter. Now, bring the back edge “P” clip (USB end) of the 2nd counter down until it clicks into the 1st counter’s slot. These two counters are now mated.
2.3.1.3 USB Connections For Stacked Configurations All stacked counters need a USB connection. A standard hub may be useful for multi-channel stacks to get enough USB ports. Each counter needs about 200mA. Plugging more than 2 counters into a hub will mean that the hub may need to be powered externally. Please refer to the hub’s documentation for more details about the power available per port. 2.3.1.
The “about” tab lists all the counters that have been found. The list shows the serial number and revision data for each counter. Elan Digital Systems Ltd.
2.3.1.
2.3.2 Non-Stacked (MIS) Mode It is also possible to use multiple USBcount50s as independent instruments. In this mode, the counters are NOT connected together via the stacking interface4. This configuration is also termed Multi-Instrument mode or MIS mode. In MIS mode, each counter can use its own timebase setting, and each counter input will remain electrically isolated from the others (unless you connect their BNC grounds together). 2.3.2.
where “p” is the COM port number and “c” is the assigned channel number. For example, if you want to run 2 counters in MIS mode, use Window’s Device Manager to get the two COM port numbers for the two counters (see 3.2). Lets assume they are COM4 and COM5. Next, locate the USBcount50.exe program (normally under “Program Files\USBcount50”) and highlight the file. Right click the file and use “Create Shortcut” to make TWO shortcuts to the program.
2.4 Input Control 2.4.1 Input Supply The USBcount50 supports a programmable input supply via the slider control. Supplies from 1.50V to 5.00V are possible, and the slider control adjusts in 256 steps of 13.67mV per step. This range allows the user to match against common industry standard logic levels present in their circuit to be measured6.
2.5 Counter Modes 2.5.1 General In RUN mode, the counter continually display readings (assuming these is an input signal of course). Clicking ONCE, takes a single reading and then places the counter into STOP mode, so that further readings cease.
Green means the reading is done. Red means the reading over-flowed i.e. external period too long or external frequency too high. Try a shorter internal period or lower internal frequency. If the counter waits for more than 2 seconds whilst in Period mode and no external signal has been detected, the indicator will blink rapidly white-grey-white-grey etc. Elan Digital Systems Ltd.
2.5.2 Frequency Mode The counter can be put into Frequency mode using the selection button shown below. Note too that clicking on a new period selection item will change to Frequency mode. In this mode of operation, the counter will use an internally generated gating period of 0.1s, 1s or 10s, to integrate (count) pulses that arrive at the input during the period.
2.5.3 Period Mode Period mode uses an internally generated reference clock to time the period between two edges on the input waveform. It is selected as shown. The reference clock can be selected from 100MHz, 10MHz or 1MHz.
Period mode should be used if you have a single pulse or a slow input frequency. In the latter case, by timing the period from edge to edge allows a very accurate measurement of low frequencies by simply inverting the period measured. This is known as reciprocal mode. The software shows this reciprocal. Elan Digital Systems Ltd.
2.5.4 Period Mode 3 SOFTWARE INSTALLATION 3.1 Windows 98SE and Windows Me Before plugging in the hardware: Use the supplied install CD and run the setup program. This will copy all the required files and drivers to your PC. After running the setup program: Insert the USBcount50 into a free USB socket, or into a USB hub port. A USB extension cable can be used if needed.
Once the hardware has installed, there is no need to make any settings for the allocated COM port…the software takes care of all this at run time. Start the USBcount50 software and you will see the following display9: To find out what the various buttons and knobs do, simply hover over them for a brief explanation. 9 A 2 channel example is shown Elan Digital Systems Ltd.
3.2 Windows 2K and XP10 Before plugging in the hardware: Use the supplied install CD and run the setup program. This will copy all the required files and drivers to your PC. After running the setup program: Insert the USBcount50 into a free USB socket, or into a USB hub port. A USB extension cable can be used if needed. During installation, two hardware devices are detected: The “USBcount50 Composite Device” first, followed by the “USBcount50” itself.
Once the hardware has installed, there is no need to make any settings for the allocated COM port…the software takes care of all this at run time. Start the USBcount50 software and you will see the following display13: To find out what the various buttons and knobs do, simply hover over them for a brief explanation. 13 A 1 channel example is shown Elan Digital Systems Ltd.
3.3 Troubleshooting • Check that the counter hardware installed properly. Use the device manager as shown above and check that there are no yellow exclamation marks on any of the USBcount50 devices. If there are, try deleting that device, then un-plug and re-plug the counter. • Make sure that you do not press cancel or stop during any part of the hardware installation.
4 HARDWARE SPECIFICATION All parameters typical @ 20°C unless otherwise stated 4.1 Power Requirements Supply Voltage: Total Supply Current: 5.0V ±10% from host USB bus 200mA avg 4.2 Mechanical Mass: Case Material Data: Size (typical in mm): 42g typ. Polycarbonate (UL94V rated) 99.615 x 30.6 x 17.516 4.
4.4 Performance 4.4.1 Safety Data and Maximum Ratings Important Safety Precautions Always observe these when using the USBcount50 The USBcount50 contains no user serviceable parts inside. Do not open the plastic housing. There may be lethal voltages inside the plastic housing. Do not use the instrument if the housing is damaged or is poorly fitting. In such a case do not connect anything to the USBcount50 to avoid a hazard. The USBcount50 will have to be repaired or replaced in such a situation.
Isolation rating: Transient isolation17: 300V CAT II, 500V CAT I between BNC ground and USB ground BNC ground to USB ground +/-2.5KV 4.4.2 Performance Measurement modes: Frequency and Period RUN mode: STOP mode: ONCE mode: Continuous readings Readings frozen Single reading returning to STOP Input connector: Input DC resistance: BNC 1Meg to GND for inputs between (GND-0.4V) and (INPUT SUPPLY + 0.4V).
4.4.4 Software USBcount50 support: Recommended system: Win98SE/Me/2000/XP Pentium Class 600MHz or better, 16-Bit colour depth graphics or better with graphics acceleration, 800x600 min screen resolution, 256MBytes RAM USBcount50 registry hive: HKEY_CURRENT_USER\Software\VB and VBA Program Settings\USBcount50 (this key is deleted during un-install) Elan Digital Systems Ltd.
