Microlink 302x Hardware User Manual
Contents
1. CARRY Outputs You can count more than 65535 events by cascading two or more counters Connect the CARRY output of one counter to the CLOCK input of the next Leave the ENABLE input of this second counter unconnected The CARRY output is a high going pulse lasting for 256 input counts The falling edge marks the actual carry point 4 3 Microlink 3000 Hardware User Manual Table 4 1 3020 3021 8 Counters Pin Connections for 37 Way D Plug Wiring View 19 OV 5V 37 18 unused unused 36 17 unused unused 35 16 CARRY 0 CLOCK 0 34 15 ENABLE 0 unused 33 14 CARRY 1 CLOCK 1 32 13 ENABLE 1 unused 31 12 CARRY 2 CLOCK 2 30 11 ENABLE 2 unused 29 10 CARRY 3 CLOCK 3 28 9 ENABLE 3 unused 27 8 CARRY 4 CLOCK 4 26 7 ENABLE 4 unused 25 6 CARRY 5 CLOCK 5 24 5 ENABLE 5 unused 23 4 CARRY 6 CLOCK 6 22 3 ENABLE 6 unused 21 2 CARRY 7 CLOCK 7 20 1 ENABLE 7 Please read the Connection Notes on the previous pages before making your connections 4 4 Counters and Timers 4 2 3022 24 Bit Counter The 3022 module provides a single 24 bit counter which can be ei ther an up down counter a frequency counter a period timer or a start stop timer Use software to select the type of counter or timer When in up down counter mode the direction of counting can be con trolled either by software or by a hardware input A gate input is also available to enable or disable counting An output is provided to indi2. cate when the counter reaches zero In frequency mode 4 gate times are available 0 01 0 1 1 0 and 10 seconds The module will count the number of cycles occurring at its input during these gate times At the end of a gate time the output latches are updated the count is reset to zero and the measurement restarts In period mode the module measures the time for 1 10 100 or 1000 cycles of the input signal The unit of measurement is 0 1 microsec onds At the end of each measurement the output latches are updated the counter is reset to zero and the measurement restarts In timer mode the module measures the time that a signal is true or the time between a start and stop pulse The unit of measurement is 0 1 microseconds 4 2 1 Connection Notes Inputs All inputs are TTL 5 V CMOS compatible They are all pulled high by 100 K resistors Voltages applied should be restricted to the range 0 5 V Outputs All Outputs are TTL and 5 V CMOS compatible They are capable of driving 10 LSTTL loads 4 5 Microlink 3000 Hardware User Manual Main Counter Controls There are three signals COUNT DOWN UP and ENABLE In up down counter mode a positive edge at the COUNT input will ad vance the counter if the ENABLE input is high Changes of state on the ENABLE input will not cause false counts The module will count up if the DOWN UP input is low It will count down if the DOWN UP input is high In frequency or period mode the m
3. flip flop is CLOCK D Not Not Q Not Q SET RESET X X 1 0 0 1 X X 0 1 1 0 X X 0 0 1 1 0 1 1 0 1 1 1 1 1 0 In timing applications three points must always be considered 1 How to start the timing 2 How to stop the timing 3 How to initialise the counter to stop before start occurs Some examples are given below Timing with Separate Start and Stop Pulses Not Set CLOCK Not Q Not Reset STOP D7 OUTPUT Figure 4 1 Timing with Separate Start and Stop Pulses 4 7 Microlink 3000 Hardware User Manual The D7 OUTPUT is used to initialise the FF to the stop state A negative going pulse sets the FF and so starts the timing A rising edge at the CLOCK resets the FF and so stops the timing The Q of the FF controls the ENABLE and so the timing Software Start Hardware Stop START to EXTERNAL UNIT Not Set D7 OUTPUT C C i ENABLE D6 OUTPUT C CLOCK Not Q Not Reset Figure 4 2 Software Stop Hardware Stop The FF can be initialised by setting the D7 OUTPUT low and producing a positive edge on D6 OUTPUT Software start is produced by setting D7 OUTPUT high and producing a positive edge on D6 OUTPUT A low level on Not RESET stops the unit The Q output of the FF can be used to trigger the system being investigated 4 8 Counters and Timers Start and Stop Pulses on the Same Line ENABLE START STOP es ee oes CLOCK Not Q No
4. 1 MHz crystal oscillator 0 01 0 1 1 and 10 seconds 1 24 bits up down frequency start stop period 10 MHz TTL and 5 V CMOS Oto5V 10 LSTTL loads 1 MHz crystal oscillator 0 01 0 1 1 and 10 seconds frequency mode only 1 10 100 or 1000 period mode only
5. MICROLINK 302x Timing and Counting User Manual Biodata Limited Manual Code M3000 3 2 Issue Date December 1998 Information in this document is subject to change without notice Updates are listed on our web site at http Awww microlink co uk techsupp html Biodata Limited 1990 2005 10 Stocks Street Manchester M8 8QG Tel 0161 834 6688 Fax 0161 833 2190 Email sales microlink co uk http www microlink co uk Counters and Timers Counters and Timers The 302x range provides numerous timing and counting options There are 3 modules in the range the 3020 3021 and 3022 The 3020 has 8 independent 16 bit counters Each counter is an event totalise counter and can be individually read and reset The counts can be cascaded to allow longer counts The 3021 also has 8 independent 16 bit counters These can be used in one of 2 modes event or frequency The 3022 has 1 counter which can be used in one of 4 modes frequency period up down counter or timer The operating mode is set from software All the modules have 37 way D type connectors Alternatively you can connect your signals to screw terminals with a 390x module The 390x modules also provide extra facilities such as input protection when the appropriate components are fitted See Chapter 11 for details 4 1 Counters and Timers 4 1 3020 3021 Eight 16 Bit Counters The 3020 provides 8 independent 16 bit counters which can each
6. count up to 65535 The counters are event counters The 3021 has 8 counters of 16 bit resolution which can be either event or frequency counters At power up all counters will be in event mode Each counter can be individually set into event or frequency mode from software In frequency mode 4 gate times are available 0 01 0 1 1 and 10 seconds On the 1 second range for example the 3021 will count the number of input cycles occurring in 1 second Each counter of both the 3020 and 3021 has a CLOCK input an ENABLE input and a CARRY output 4 1 1 Connection Notes The connections for the 3020 and 3021 are identical Input Voltages The inputs are TTL and 5 V CMOS compatible Each input is pulled high by a 100K resistor The input voltages should not go outside the 0 to 5 V range The 3900 Screw Terminal module can be used to mount components providing input protection or higher voltage inputs Opto Isolated Inputs These can be provided by the 3801 isolated input module Outputs The carry outputs are TTL and 5 V CMOS compatible They are capable of driving 10 LSTTL loads CLOCK Inputs The counters advance on falling edges at their clock inputs 4 2 Counters and Timers ENABLE Inputs Acounter can only advance when its enable input is high The 100K pull up resistors fitted to these inputs mean that they can be left unconnected if not required Changes of state at the enable inputs will not cause the counter to advance
7. easured signal should be applied to the COUNT input The ENABLE and DOWN UP inputs are not re quired and are internally disconnected In timer mode the COUNT input is internally switched to the 10 MHz clock The DOWN UP input is internally disconnected The ENABLE input controls the timing since the counter advances at 10 MHz when ever the ENABLE is high The DOWN UP input and the ENABLE input are read by software In modes where the ENABLE or DOWN UP in puts are internally disconnected they may be used as auxiliary inputs In the 3300 Programming Manual the ENABLE input is called START STOP ZERO Outputs The ZERO output goes high when the counter contains 0 The Not ZERO is simply its inverse D4 5 6 7 OUTPUTS These four output lines are controlled by software In IML software D5 OUTPUT is designated DOWN UP output It is intended to be con nected to the DOWN UP input to give software direction control Likewise D6 OUTPUT is designated START STOP output and is in tended for connection to the ENABLE input These connections should only be made when required by the application D7 OUTPUT is unique in that it can also be read by the software as D7 of the mode byte Any of these outputs can be freely used as required by the application 4 6 Counters and Timers Timing Flip Flop Two outputs and four inputs give full control over a D type flip flop 74HC74 which is useful for timing applications The Truth Table of the FF
8. t Reset D7 OUTPUT C Figure 4 3 Start and Stop Pulses on the Same Line The FF can be initialise by setting D7 OUTPUT low The FF then changes state at each rising edge on its CLOCK input 4 9 Microlink 3000 Hardware User Manual Table 4 2 3022 1 24 Bit Counter Pin Connections for 37 Way D Plug Wiring View 19 OV 5V 37 18 FF Not Q unused 36 17 FFQ Not ZERO 35 16 FF CLOCK ZERO 34 15 FF Not SET unused 33 14 FF D unused 32 13 FF Not RESET unused 31 12 COUNT unused 30 11 DOWN UP unused 29 10 ENABLE unused 28 9 D5 OUTPUT unused 27 8 D6 OUTPUT unused 26 7 D7 OUTPUT unused 25 6 10 MHz unused 24 5 D4 OUTPUT unused 23 4 unused unused 22 3 unused unused 21 2 unused unused 20 1 unused Please read the Connection Notes on the previous page before making your connections 4 10 Counters and Timers 4 3 302x Specifications 4 3 1 3020 and 3021 Specifications Number of counters Resolution Event counter Frequency counter Maximum input frequency Compatibility Input voltage range Carry outputs drive 3021 Frequency Measurement Clock reference Gate times 4 3 2 3022 Specifications Number of counters Resolution Counter type Maximum input frequency Compatibility Input voltage range Carry outputs drive Clock reference Gate times Number of cycles timed 8 16 bits 3020 and 3021 3021 only 10 MHz TTL and 5 V CMOS Oto5V 10 LSTTL loads
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