Campbell SDM-SW8A Скачать руководство пользователя страница 5

SDM-SW8A Switch Closure Input 
Module 

1.  Function 

The 8 channel SDM-SW8A Switch Closure Input Module (see Figure 1) 
measures up to 8 channels of switch closure or voltage pulse inputs.  Each 
channel may be configured to read single-pole double-throw (SPDT) switch 
closure, single-pole single-throw (SPST) switch closure, or voltage pulse.  
Output options include counts, duty cycle, and state. 

The SW8A is addressed by the datalogger, allowing multiple SW8As to be 
connected to one datalogger (refer to Theory of Operation, Section 9).  Sixteen 
addresses are available, but for most applications, Campbell Scientific, Inc. 
recommends no more than 4 SW8As be connected to one datalogger.  If more 
SW8As are required, please consult Campbell Scientific's Marketing 
Department. 

In October, 1988, the SDM-SW8A was introduced.  Edlog Instruction 102 is 
used for communication with the SW8A.  CRBasic dataloggers use the 
SDMSW8A instruction.  Previous to October, 1988, the SDM-SW8 (no "A") 
was offered for use only with the CR10, utilizing CR10 I/O Instruction 15. 

 

SDM-SW8As are not compatible with CR10s containing Instruction 15, 
and SDM-SW8s are not compatible with CR10s containing Instruction 
102.

  Contact Campbell Scientific's Marketing Department for update options 

if incompatibilities exist.  

 

FIGURE 1.  SDM-SW8A Front Panel 

Содержание SDM-SW8A

Страница 1: ...on 7 10 12V C3 C2 C1 IN 5V IN 1 5V IN 2 5V IN 3 5V IN 4 5V IN 5 5 V IN 6 5 V IN 7 5 V IN 8 C1 OUT TO DATALOGGER 8 CHANNEL SWITCH CLOSURE INPUT MODULE SDM SW8A MADE IN USA C o p y r i g h t 1 9 8 7 2 0...

Страница 2: ...tional customers residing in countries served by Campbell Scientific Inc directly Affiliate companies handle repairs for customers within their territories Please visit www campbellsci com to determin...

Страница 3: ...nsor Connections 4 5 Internal Jumpers 4 5 1 Address Jumpers 4 5 2 Measurement Jumpers 6 6 Datalogger Programming 6 6 1 CRBasic Programming 6 6 1 1 SDMSW8A Instruction 6 6 1 2 SDMSpeed Instruction 7 6...

Страница 4: ...Connections 3 3 Address Jumpers 5 4 Measurement Jumpers 6 5 Bit Period Values 8 6 Instruction 102 SDM SW8A 9 List of Figures 1 SDM SW8A Front Panel 1 2 SDM SW8A Address and Port Configuration Jumpers...

Страница 5: ...ilable but for most applications Campbell Scientific Inc recommends no more than 4 SW8As be connected to one datalogger If more SW8As are required please consult Campbell Scientific s Marketing Depart...

Страница 6: ...unce time 3 ms open without counting Output options State duty cycle counts Max count port 65535 Internal sampling frequency 500 Hz Watchdog reset Yes Total length of connecting cables 20 feet Dimensi...

Страница 7: ...e jumper connecting C1 IN to C1 OUT 3 Power Supply Considerations Due to the 3 mA continuous and 6 mA active current drain an auxiliary 12 VDC power supply is recommended for powering the SW8A in remo...

Страница 8: ...e cable lengths connecting SW8As or other SDM devices and a datalogger should be as short as possible and preferably does not exceed 20 ft Longer lead lengths may be possible for CRBasic dataloggers i...

Страница 9: ...c nc 02 c c nc c 03 c c nc nc 10 c nc c c 11 c nc c nc 12 c nc nc c 13 c nc nc nc 20 nc c c c 21 nc c c nc 22 nc c nc c 23 nc c nc nc 30 nc nc c c 31 nc nc c nc 32 nc nc nc c 33 nc nc nc nc c connect...

Страница 10: ...pport software 6 1 CRBasic Programming 6 1 1 SDMSW8A Instruction The SDMSW8A instruction is used to control the SDM SW8A Eight Channel Switch Closure module and store the results of its measurements t...

Страница 11: ...iplier and offset by which to scale the raw results of the measurement See the measurement description for the units of the raw result a multiplier of one and an offset of 0 are necessary to output in...

Страница 12: ...m Allowable Bit Period Maximum Bit Period CR800 CR850 26 04 sec 8 68 sec 2 2 msec CR1000 26 04 sec 8 68 sec 2 2 msec CR3000 26 04 sec 8 68 sec 2 2 msec CR5000 30 sec 8 sec 3 msec The equation used to...

Страница 13: ...continues to the next SW8A The address settings for the SW8As must be sequential For example assume two SW8As with addresses of 22 and 23 are connected and 12 Reps are requested Eight channels from th...

Страница 14: ...state every 2 ms and accumulates the information for duty cycle and counts Each channel has one 16 bit accumulator for duty cycle and one for counts The accumulators are reset when the datalogger requ...

Страница 15: ...e Module For example if the datalogger scan rate is 10 minutes and 2 channels of counts are requested the SW8A may stay bombed for 20 minutes To avoid this undesirable time delay before resetting a tr...

Страница 16: ...g 9 EndTable SUBROUTINES Sub Subroutine1 SDMSW8A state 8 0 0 1 1 0 SDMSW8A duty 8 0 1 1 1 0 SDMSW8A counts 8 0 2 1 1 0 EndSub PROGRAM BeginProg Scan 1 Sec 3 0 Call Subroutine1 IfSDM SW8Awasjustprogram...

Страница 17: ...elation to the signal conditioned by the SW8A FIGURE 3 SPDT Signal Conditioning by SDM SW8A The 5V output located next to each of the 8 input channels is for biasing in the SPDT measurement A 200 Ohm...

Страница 18: ...or of 2 duty cycle samples on any measurable cycle Equations given below estimate the worst case duty cycle measurement error for a 50 duty cycle and the minimum maximum measurable duty cycle for a gi...

Страница 19: ...e command part providing it is valid For Function Options 1 and 2 the module receives another byte containing Reps and Channel information from the datalogger For a valid address and command the SW8A...

Страница 20: ...SDM SW8A Switch Closure Input Module 16...

Страница 21: ...ected in the first Location containing SW8A data and Flag 9 is set high The SW8A is accessed a second time to increment the watchdog counter to greater than 64 and force a watchdog reset refer to Sect...

Страница 22: ...TE 3 15 DUTY 7 4 STATE 4 16 DUTY 8 5 STATE 5 17 COUNT 1 6 STATE 6 18 COUNT 2 7 STATE 7 19 COUNT 3 8 STATE 8 20 COUNT 4 9 DUTY 1 21 COUNT 5 10 DUTY 2 22 COUNT 6 11 DUTY 3 23 COUNT 7 12 DUTY 4 24 COUNT...

Страница 23: ...3 0 F 4 19 Set high Flag 9 OUTPUT STATE AND AVERAGE DUTY CYCLE EVERY 5 MINUTES 4 If time is P92 1 0 minutes into a 2 5 minute interval 3 10 Set high Flag 0 output 5 Real Time P77 1 110 Day Hour Minute...

Страница 24: ...le P70 1 1 Reps 2 25 Loc RESET CNT 15 Do P86 1 21 Set low Flag 1 FIRST SCAN ROUTINE 16 Else P94 17 Do P86 1 11 Set high Flag 1 18 End P95 19 End P95 20 End Table 1 Table 3 Subroutines SUBROUTINE TO ME...

Страница 25: ...DM SW8A P102 1 8 Reps 2 00 Address 3 1 Duty cycle function 4 1 Chan 5 9 Loc duty 1 6 1 Mult 7 0 Offset 4 SDM SW8A P102 1 8 Reps 2 00 Address 3 2 Counts function 4 1 Chan 5 17 Loc counts 1 6 1 Mult 7 0...

Страница 26: ...Appendix A Edlog Program Example A 6...

Страница 27: ......

Страница 28: ...p CSC 11564 149th Street NW Edmonton Alberta T5M 1W7 CANADA www campbellsci ca dataloggers campbellsci ca Campbell Scientific Centro Caribe S A CSCC 300 N Cementerio Edificio Breller Santo Domingo Her...

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