a AN-535 application note one technology way ? p.o. box 9106 ? norwood, ma 02062-9106 ? 781/329-4700 ? world wide web site: http://www.analog.com digital input/output subsystems introduction the db-16 and db-24 are 16- and 24-channel digital i/o subsystems providing a reliable, solid state, optically isolated interface between data acquisition boards, such as the analog devices rti-800 series, or distributed i/o signal conditioning subsystems such as the analog devices model 6b50, and discrete high level i/o. the db-16 is a manifold card that accepts up to 16 single-channel digital input and output modules. these solid state relay modules can be mixed and matched to provide an interface to ac inputs, ac outputs, dc inputs and dc outputs. each i/o module is individually con- trolled or sensed by the digital i/o of the data acquisition board or the 6b50 subsystem. the db-24 is a manifold card that can accept up to six 4-channel (quad) digital input and output modules. these modules can be mixed and matched as well. each module handles four channels of identical levels, and the state of each input or output can be observed via the four leds on each module. the db-16 and db-24 share the same pinout and 50-pin card edge connector and can be used interchangeably. however, only the 16 channels are addressable on the db-16. an external +5 v dc power supply at 300 ma maximum is required for operation. db-16 digital i/o subsystem use the db-16 digital i/o backplane, shown in figure 1, and its associated ac and dc single-channel i/o modules to measure and/or control high level ac and dc signals or if isolation of the digital i/o is required. single-channel solid state relays the db-16 supports the installation of up to 16 single- channel, solid-state relay modules, which provide 2500 v peak of optical isolation. you should install the modules in their appropriate positions in the backplane and secure them with one screw each. all output modules can switch up to three amps. ac out- put modules provide zero voltage turn-on and have an rc (resistor-capacitor) snubber network for increased capability with inductive loads. ac and dc input mod- ules are designed with filtering on the input and hyster- esis for high noise rejection and transient-free clean switching. they are designed so that high voltage tran- sients on the input do not cause damage to the module. each module operates by negative true logic, in which a low digital voltage turns on current to the module. indi- vidual led status indicators monitor module activity and light when the current is active. each i/o module position on the db-16 backplane has a 5 amp, 250 v rms pico-fuse (littelfuse ? part number 251 005) protecting the module and wiring from short circuits. 49 1 key slot 0123456 7 8 9 10 11 12 13 14 15 barrier strip for logic supply input power barrier strip power line fuse, 5 amp pull-up resistor 3.3k v signal card edge connector figure 1. db-16 digital i/o backplane all trademarks are the property of their respective holders.
C2C AN-535 table i lists the input and output modules available for use with the db-16 backplane. table i. single-channel input/output module summary output input type model range current current input id016 4 vC16 v dc 68 ma id032 10 vC32 v dc 34 ma ia140a 90 vC140 v ac 5 ma 90 vC140 v dc ia280a 180 vC280 v dc 180 vC280 v ac 5 ma output od060 5 vC60 v dc 3.0 a rms oa140a 12 vC140 v ac 3.5 a rms oa280a 24 vC280 v ac 3.5 a rms attaching digital i/o applications to the db-16 backplane the db-16 backplane is powered through an external +5 v dc power supply. applications to the db-16 back- plane are connected through the screw terminal barrier strip, which contains 32 standard slot-head screw termi- nals (screw terminals 1 and 2 are associated with chan- nel 0 on the backplane; screw terminals 3 and 4 are associated with channel 1 on the backplane, and so on). use the odd-numbered screw terminal for the high in- put; use the even-numbered screw terminal for the low input. figure 2 illustrates high level ac and dc digital wiring us- ing input and output modules on the db-16 backplane. example 2a illustrates turning a lamp on or off; example 2b illustrates monitoring whether the lamp is on or off; example 2c illustrates turning a relay coil on and off; and example 2d illustrates monitoring whether or not a relay coil is energized. input module 4 14 115v ac pull-up resistor socketed pico fuse (5a) led screw #29 #30 b. ac input output module 4 15 current limit resistor 1 115v ac screw #31 #32 led output module 4 13 +24v dc 2 relay coil 3 screw #27 #28 led a. ac output input module 4 12 115v dc led screw #25 #26 c. dc output d. dc input notes: 1 should not exceed 3a. 2 user supplied diode necessary for inductive spike damping. 3 relay coil amperage should not exceed output module rating. 4 modules are color coded: ac input ac output C black dc input dc output C white C red C yellow figure 2. typical high-level digital i/o wiring examples using the db-16 backplane
C3C AN-535 db-24 digital i/o subsystem use the db-24 digital i/o manifold card, shown in figure 3, and its associated dc and ac 4-channel i/o modules to measure and/or control high level ac and dc signals or if isolation of the digital i/o is required. 4-channel solid state relays the db-24 is a 24-channel i/o backplane that supports the installation of up to six 4-channel, high-density mod- ules to perform ac input, dc input, dc output, and dc out- put functions. you install each module into a socketed position on the db-24 backplane, where each module is held in place with two screws, provided with the module. all output modules are able to switch up to 3 amps. ac output modules provide zero voltage turn-on and have an rc snubber network for increased capability with in- ductive loads. ac and dc input modules are designed with filtering on the input and hysteresis for high noise rejection and transient free clean switching. they are designed so that high voltage transients on the input will not cause damage to the module. optical isolation for the ac and dc input and output module is rated at 4000 v rms input-to-output. each module is color-coded by function and the model number is clearly marked on the module itself. the channel numbers associated with the module are printed below the module on the panel and spaces are 13 24 13 24 13 24 13 24 13 24 13 24 to digital i/o connector +5v and gnd key slot 49 1 j1 25 23 0C3 4C7 8C11 12C15 16C19 20C23 fuse 1a fuse 5a barrier strip 1c35c79c11 2c46c810c12 13c1517c1921c23 14 c 16 18 c 20 22 c 24 figure 3. db-24 digital i/o backplane provided to apply colored stick-on dots (supplied) to match the color coding of the modules (yellow = ac in- put, black = ac output, white = dc input, and red = dc output). note that the four channels corresponding to one quad module must be configured with either all in- put channels or all output channels. each module on the db-24 digital i/o backplane oper- ates by negative true logic, in which a low digital voltage turns on current to the module. four leds on each mod- ule indicate the status of the i/o channels (the led lights when current is turned on). each i/o module position has two 5 amp, 250 v rms pico- fuses protecting the module and wiring from short cir- cuits. table ii lists the input and output 4-channel modules available for use with the db-24 backplane. table ii. quad input/output module summary output input type model range current current input id16fq 4 vC32 v dc 68 ma id32q 10 vC60 v dc 34 ma ia120qa 90 vC140 v ac 90 vC140 v dc 5 ma ia240qa 180 vC280 v dc 180 vC280 v ac 5 ma output oa240qa 24 vC280 v ac 3.5 a rms od60q 3 vC60 v ac 3.5 a rms
C4C AN-535 powering the db-24 backplane you can power the db-24 digital i/o backplane internally for some boards, or you can use an external +5 v power supply. before you attach the db-24 backplane to the board, you must configure it for internal or external power. to configure the db-24 for internal power, remove the socketed 1 amp fuse from the left of the +5 v dc and gnd screw terminals. install this fuse in the socketed position to the right of the +5 v dc and gnd screw termi- nals on the db-24 backplane. to configure the db-24 backplane for external power, ensure that the socketed 1 amp fuse is installed to the left of the +5 v dc and gnd screw terminals. refer to figure 4. attaching the db-24 digital i/o backplane to attach the db-24 backplane to a data acquisition or 6b50 board, use a 50-pin cable, such as the ac1585-9 cable or the cab-03 cable (available from analog devices). attach one end of the cable to the digital i/o connector on the board and attach the other end of the cable to the digital i/o connector (j1) on the db-24 back- plane. make sure that pin 1 on the cable corresponds to pin 1 on the connector. refer to figure 5. 13 24 13 24 13 24 13 24 13 24 13 24 install 1a fuse for internal power key slot 49 1 j1 25 23 0C3 4C7 8C11 12C15 16C19 20C23 install 1a fuse for external power +5v external power supply 13 24 13 24 13 24 figure 4. positioning fuse for internal or external power on the db-24 backplane board j1 connector pin 1 13 24 13 24 13 24 db-24 backplane pin 1 cab-03 or ac1585-9 cable 13 24 13 24 13 24 13 24 13 24 13 24 figure 5. attaching the db-24 digital i/o backplane
C5C AN-535 attaching digital i/o applications to the db-24 i/o backplane use the db-24 digital i/o backplane for high level ac or dc signals. connect applications to the backplane through the barrier strip. the barrier strip contains stan- dard slot-head screw terminals, six screws for each 4-channel (quad) i/o module. use 22-14 awg twisted- pair wire, and strip the wire back approximately 0.25-inch (6.3 mm). four consecutive input or output ap- plications are attached to a single quad module, with two channels sharing the same common in the module. the two common connections for each module are con- nected to one another on the db-24 backplane. there- fore, each of the four individual channels on the module can use either of its two common connections. since the commons are connected, you must make sure that all of the applications attached to a 4-channel module share the same common voltage reference. if two applications use different common voltage references, the applica- tions must be attached to two different modules. figure 6 illustrates how the channels and their commons are connected. 13 24 0C3 1c3 2c4 1 2 3 8 9 10 i/o channel common 2 c 4 1 c 3 figure 6. db-24 backplane common connections figure 7 illustrates high level ac and dc digital wiring us- ing input and output modules on the db-24 backplane. example 7a illustrates turning a lamp on and off, and example 7b illustrates monitoring whether the lamp is on or off. example 7c illustrates turning a relay coil on and off, and example 7d illustrates monitoring whether or not the relay coil is being energized. note: the channels on the screw terminals on the db-24 back- plane are labeled from 1C24, while the channels for the i/o modules are labeled 0C23. keep this distinction in mind when installing your field wiring applications. 13 24 0C3 1c3 2c4 115v ac current limit resistor 1 115v ac +24v dc 2 relay coil 3 notes: 1 should not exceed 3a. 2 user supplied diode necessary for inductive spike damping. 3 relay coil amperage should not exceed output module rating. 4 modules are color coded: ac input ac output C black dc input dc output C white C red C yellow a. ac output b. ac input c. dc output d. dc input 13 24 0C3 1c3 2c4 13 24 0C3 1c3 2c4 13 24 0C3 1c3 2c4 i l 115v dc figure 7. typical high level digital i/o wiring using the db-24 and 4-channel solid state relay modules
C6C AN-535 1 2 3 4 5 1 2 3 4 5 6 7 8 9 10 1112 13 14 1516 1718 19 20 2122 2324 2526 2728 2930 3132 logic supply barrier strip C + all even pins edge conn bottom logic gnd top +logic 1 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 1 2 3 4 5 5 amp fuse (24) 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 +logic signal input/output pull-up resistor 3.3k v (24) led indicator (24) power input/output figure 8. schematic diagram model db-16 2 9 1 8 3 10 2 9 1 8 3 10 2 9 1 8 3 10 2 9 1 8 3 10 2 9 1 8 3 10 2 9 1 8 3 10 5 12 4 11 6 13 7 14 5 12 4 11 6 13 7 14 5 12 4 11 6 13 7 14 5 12 4 11 6 13 7 14 5 12 4 11 6 13 7 14 5 12 4 11 6 13 7 14 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 pins 2-50 tied to com 5 amp fuses (12) 1 3 c 5 7 c 9 11 c 13 15 c 17 19 c 21 23 c 2 4 c 6 8 c 10 12 c 14 16 c 18 20 c 22 24 c lower power barrier strip upper power barrier strip 1 amp fuse +C signal input/output edge connector figure 9. schematic diagram model db-24
C7C AN-535 single-channel solid state relays 12k v 220 v ac input + plug-in module 3.3k v led fuse screw terminals edge connector mounting backplane ac hi input ac lo input +v cc dout dig gnd a. ac input module 220 v ac output + plug-in module 3.3k v led fuse screw terminals edge connector mounting backplane ac hi output ac lo output +v cc din zero voltage circuit load b. ac output module r c dc input + plug-in module 3.3k v led fuse screw terminals edge connector mounting backplane dc hi input dc lo input +v cc dout dig gnd 1k v c. dc input module r c dc output + plug-in module 3.3k v led fuse screw terminals edge connector mounting backplane dc hi output dc lo output +v cc din amplifier load + commutating diode i out b. dc output module figure 10. outline dimensions dimensions shown in inches and (mm). 1.0 (25.4) 4-40 hold down screw 1.7 (43.2) 1.25 (31.8) 0.25 (6.4) 0.6 (15.2) 0.1 (2.54) grid 5 321 4
C8C AN-535 printed in u.s.a. e3298C5C4/98 schematic drawings logic gnd out 3 out 4 +vcc in 4 common in 3 logic gnd out 3 out 4 +vcc in 4 common in 3 r1 figure 11. input modules, id16fq, id32q, ia120qa, ia24qa in 3 in 4 +vcc out 4 common out 3 snub snub snub snub in 1 in 2 +vcc out 2 common out 1 figure 12. ac output module, oa240qa in 3 in 4 +vcc out 4 (C) common (+) out 3 (C) in 1 in 2 +vcc out 2 (C) common (+) out 1 (C) figure 13. dc output module, od60q outline dimensions dimensions shown in inches and (mm). tolerance: 0.020 ( 0.50) 0.2 (5.1) 0.5 (12.7) 2.9 (73.2) 0.042 (1.1) dia. pins 4C40 3 0.75 (19.1) pan head screw case colors: input modules: output modules: ac: yellow dc: white ac: black dc: red 0.125r 1.9 (47.5) 0.45 (11.43) 0.2 (5.1) 0.3 (7.6) 0.2 (5.1) 0.4 (10.2) 0.9 (22.9) 1.1 (27.9) 2.1 (53.3) 1.3 (33.0) 13 12 11 10 9 8 321 65 4
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