AN-535

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 controlled 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. All trademarks are the property of their respective holders. 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 singlechannel, 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 output modules provide zero voltage turn-on and have an RC (resistor-capacitor) snubber network for increased capability with inductive 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 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. Individual 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. POWER BARRIER STRIP BARRIER STRIP FOR LOGIC SUPPLY INPUT 49 POWER LINE FUSE, 5 AMP SIGNAL CARD EDGE CONNECTOR KEY SLOT 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 PULL-UP RESISTOR 3.3k Figure 1. DB-16 Digital I/O Backplane 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 Type Input Model ID016 ID032 IA140A IA280A Output OD060 OA140A OA280A Range 4 V–16 V dc 10 V–32 V dc 90 V–140 V ac 90 V–140 V dc 180 V–280 V dc 180 V–280 V ac 5 V–60 V dc 12 V–140 V ac 24 V–280 V ac 3.0 A rms 3.5 A rms 3.5 A rms Output Current Input Current 68 mA 34 mA 5 mA 5 mA 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 backplane are connected through the screw terminal barrier strip, which contains 32 standard slot-head screw terminals (screw terminals 1 and 2 are associated with channel 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 input; use the even-numbered screw terminal for the low input. Figure 2 illustrates high level ac and dc digital wiring using 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. 115V AC SCREW #31 LED OUTPUT MODULE4 15 #32 CURRENT LIMIT RESISTOR1 SCREW #29 LED INPUT MODULE4 14 #30 115V AC PULL-UP RESISTOR SOCKETED PICO FUSE (5A) a. AC Output b. AC Input +24V DC 115V DC SCREW #27 LED OUTPUT MODULE4 13 #28 2 RELAY COIL3 SCREW #25 LED INPUT MODULE4 12 #26 c. DC Output d. DC Input NOTES: 1SHOULD NOT EXCEED 3A. 2USER SUPPLIED DIODE NECESSARY FOR INDUCTIVE SPIKE DAMPING. 3RELAY COIL AMPERAGE SHOULD NOT EXCEED OUTPUT MODULE RATING. 4MODULES ARE COLOR CODED: AC INPUT – YELLOW AC OUTPUT – BLACK DC INPUT – WHITE DC OUTPUT – RED Figure 2. Typical High-Level Digital I/O Wiring Examples Using the DB-16 Backplane – 2– AN-535 1 2 C C 3 4 5 6 C C 7 9 C 11 8 10 C 12 13 C 15 17 C 19 21 C 23 14 C 16 18 C 20 22 C 24 BARRIER STRIP FUSE 5A 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 FUSE 1A 0–3 4–7 8–11 12–15 KEY SLOT 1 25 23 16–19 20–23 49 J1 +5V AND GND TO DIGITAL I/O CONNECTOR Figure 3. DB-24 Digital I/O Backplane 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 modules to perform ac input, dc input, dc output, and dc output 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 inductive 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 provided to apply colored stick-on dots (supplied) to match the color coding of the modules (yellow = ac input, 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 input channels or all output channels. Each module on the DB-24 Digital I/O Backplane operates by negative true logic, in which a low digital voltage turns on current to the module. Four LEDs on each module 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 picofuses protecting the module and wiring from short circuits. 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 Type Input Model ID16FQ ID32Q IA120QA IA240QA Output OA240QA OD60Q Range 4 V–32 V dc 10 V–60 V dc 90 V–140 V ac 90 V–140 V dc 180 V–280 V dc 180 V–280 V ac 24 V–280 V ac 3 V–60 V ac 3.5 A rms 3.5 A rms Output Current Input Current 68 mA 34 mA 5 mA 5 mA – 3– 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 terminals 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 backplane. Make sure that Pin 1 on the cable corresponds to Pin 1 on the connector. Refer to Figure 5. 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 INSTALL 1A FUSE FOR EXTERNAL POWER 0–3 4–7 8–11 12–15 KEY SLOT 16–19 20–23 49 +5V EXTERNAL POWER SUPPLY J1 25 23 1 INSTALL 1A FUSE FOR INTERNAL POWER Figure 4. Positioning Fuse for Internal or External Power on the DB-24 Backplane 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 DB-24 BACKPLANE PIN 1 PIN 1 BOARD CAB-03 OR AC1585-9 CABLE J1 CONNECTOR Figure 5. Attaching the DB-24 Digital I/O Backplane – 4– 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 standard slot-head screw terminals, six screws for each 4-channel (quad) I/O module. Use 22-14 AWG twistedpair wire, and strip the wire back approximately 0.25-inch (6.3 mm). Four consecutive input or output applications 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 connected to one another on the DB-24 backplane. Therefore, 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 applications must be attached to two different modules. Figure 6 illustrates how the channels and their commons are connected. 1 2 C C 3 4 I/O CHANNEL COMMON 1 2 C C 3 4 1 2 3 1 2 3 4 8 9 10 0–3 Figure 6. DB-24 Backplane Common Connections Figure 7 illustrates high level ac and dc digital wiring using 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 backplane are labeled from 1–24, while the channels for the I/O modules are labeled 0–23. Keep this distinction in mind when installing your field wiring applications. 115V AC CURRENT LIMIT RESISTOR1 IL 115V AC RELAY COIL3 2 115V DC +24V DC 1 2 C C 3 4 1 2 C C 3 4 1 2 C C 3 4 1 2 C C 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 0–3 0–3 0–3 0–3 a. AC Output b. AC Input c. DC Output d. DC Input NOTES: 1SHOULD NOT EXCEED 3A. 2USER SUPPLIED DIODE NECESSARY FOR INDUCTIVE SPIKE DAMPING. 3RELAY COIL AMPERAGE SHOULD NOT EXCEED OUTPUT MODULE RATING. 4MODULES ARE COLOR CODED: AC INPUT – YELLOW AC OUTPUT – BLACK DC INPUT – WHITE DC OUTPUT– RED Figure 7. Typical High Level Digital I/O Wiring Using the DB-24 and 4-Channel Solid State Relay Modules – 5– AN-535 POWER INPUT/OUTPUT LOGIC SUPPLY BARRIER STRIP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 – + EDGE CONN BOTTOM ALL LOGIC GND EVEN PINS 5 AMP FUSE (24) 1 2 3 4 5 TOP 1 17 19 21 23 25 27 29 SIGNAL 31 INPUT/OUTPUT 33 35 37 39 41 43 45 47 +LOGIC 49 +LOGIC 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 1 2 3 4 5 PULL-UP RESISTOR 3.3k (24) LED INDICATOR (24) Figure 8. Schematic Diagram Model DB-16 1 2 C C 3 4 6 5 C C 7 8 10 9 C C 11 12 14 13 C C 15 16 18 17 C C 19 20 22 21 C C 23 24 LOWER POWER BARRIER STRIP UPPER POWER BARRIER STRIP 5 AMP FUSES (12) 1 2 3 1 AMP FUSE 4 5 6 7 11 12 13 14 4 5 6 7 11 12 13 14 4 5 6 7 11 12 13 14 4 5 6 7 11 12 13 14 4 5 6 7 11 12 13 14 4 5 6 7 11 12 13 14 8 9 10 1 2 3 8 9 10 1 2 3 8 9 10 1 2 3 8 9 10 1 2 3 8 9 10 1 2 3 8 9 10 +– 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1 PINS 2-50 TIED TO COM SIGNAL INPUT/OUTPUT EDGE CONNECTOR Figure 9. Schematic Diagram Model DB-24 – 6– AN-535 SINGLE-CHANNEL SOLID STATE RELAYS MOUNTING BACKPLANE AC HI INPUT SCREW TERMINALS AC LO INPUT FUSE 12k AC LO OUTPUT MOUNTING BACKPLANE AC HI OUTPUT LOAD SCREW TERMINALS FUSE ZERO VOLTAGE CIRCUIT PLUG-IN MODULE AC INPUT PLUG-IN MODULE AC OUTPUT LED +VCC 3.3k DOUT EDGE CONNECTOR DIG GND + 220 LED +VCC 3.3k DIN EDGE CONNECTOR + 220 a. AC Input Module b. AC Output Module MOUNTING BACKPLANE DC HI INPUT SCREW TERMINALS DC LO INPUT FUSE PLUG-IN MODULE DC INPUT DC HI OUTPUT COMMUTATING MOUNTING DIODE BACKPLANE LOAD SCREW TERMINALS DC LO OUTPUT FUSE PLUG-IN MODULE + DC OUTPUT 1k AMPLIFIER LED +VCC 3.3k DOUT EDGE CONNECTOR DIG GND DIN + RC LED +VCC 3.3k IOUT EDGE CONNECTOR + RC c. DC Input Module Figure 10. b. DC Output Module OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 1.7 (43.2) 1.0 (25.4) 4-40 HOLD DOWN SCREW 1.25 (31.8) 0.25 (6.4) 54 3 2 1 0.6 (15.2) 0.1 (2.54) GRID – 7– AN-535 SCHEMATIC DRAWINGS LOGIC OUT GND 3 OUT 4 IN 4 IN 3 IN 3 IN 4 +VCC OUT 4 COMMON SNUB SNUB OUT 3 +VCC COMMON SNUB IN 1 IN 2 +VCC OUT 2 SNUB OUT 1 COMMON Figure 12. AC Output Module, OA240QA R1 IN 3 LOGIC OUT GND 3 OUT 4 +VCC IN 4 COMMON IN 3 IN 4 +VCC OUT 4 (–) COMMON (+) OUT 3 (–) Figure 11. Input Modules, ID16FQ, ID32Q, IA120QA, IA24QA IN 1 IN 2 +VCC OUT 2 (–) COMMON (+) OUT 1 (–) Figure 13. DC Output Module, OD60Q OUTLINE DIMENSIONS Dimensions shown in inches and (mm). Tolerance: ± 0.020 ( ± 0.50) 0.125R 1.9 (47.5) 13 12 11 2.9 (73.2) 0.5 (12.7) 65 4 321 10 9 8 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) 1.3 (33.0) 0.042 (1.1) DIA. PINS 4–40 0.75 (19.1) PAN HEAD SCREW 2.1 (53.3) CASE COLORS: INPUT MODULES: AC: YELLOW DC: WHITE OUTPUT MODULES: AC: BLACK DC: RED – 8– PRINTED IN U.S.A. 0.2 (5.1) E3298–5–4/98