Download Purpose: I/O Connections

TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Purpose:
This TechNote describes the hardware configuration of the B1216 multifunction I/O module. The module
provides 8 multifunction (digital, analog, pulse) inputs and 8 digital outputs. Communications with the
module uses a 2-wire RS485 connection.
I/O Connections
Digital Outputs:
Each digital output provides an open collector circuit capable of sinking 250 ma when all are active or
350 ma individually. Each output is also capable of producing a PWM (pulse width modulation) output
having 8-bit resolution at 7.8kHz.
If an external power supply is used it should be connected to the K input (Fig 11) as well as the load. The
K connection provides clamping to minimize spikes caused by inductive loads. The other side of the load
is connected to one of the open collector digital outputs and will be switched to ground when the output is
active.
Warning - The output must never exceed the maximum voltage rating of 30VDC.
Figure 1 - Digital Output Connection
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Input Connections:
The Z1216 input connections support digital inputs, analog inputs, and pulse inputs. Pulse inputs are a
special class of inputs that invoke counting and storage. Pulse inputs have the same electrical
specifications as standard digital inputs. The mode of operation (analog, digital, or pulse) is independently
set for each input terminal under software control.
Digital Inputs: Digital inputs can be used to sense contact closure, power status or other discrete events.
The I/O module supplies an internal pull up circuit for each input as shown in Figure 2. The internal pull
up circuitry is connected to an input pin using dip switch S1 on the circuit board. For analog inputs or to
construct pull down circuitry the switch can be opened to disconnect the 10K pull up resistor.
Figure 2 - Internal Pull Up Circuit
Analog Inputs: Inputs configured to operate in analog mode apply 12 bit analog to digital conversion
across an input voltage range of 0 - 5 volts. Ctek's Automation Control application provides a calibration
feature to compensate for minor variations in the reference supply. Sensors designed for other voltage
ranges and current loop sensors such those designed for 4 - 20 ma standard can be easily adapted with
simple resistive networks.
Note - When using an external source of power for analog or digital inputs it is important to take one of
two precautions to avoid ground loops.
1 - Use a completely isolated supply
2. Connect the Z1216 ground to the external supply ground
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
RS485 Addressing
The RS485 address of a module is set under software control from the Automation Control program. Each
module leaves the factory assigned a default address of 99. See the Automation Control documentation
for additional addressing information.
Physical Layout – Connections and Indicators
Figure 3 shows a top view of the module with the major connections and indicators labeled. The S1 pull
up selection switch is found on the underside of the circuit board.
Figure 3 - Top View
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Input Connector Pin Assignments
The input connector is a double height terminal block. Figures 4 & 5 show the pin assignments.
Figure 4 - Input Connector
Top
Row
Bottom
Row
+5VDC
Input 5
Input 6
Ground
+5VDC
Input 7
Input 8
Ground
+5VDC
Input 1
Input 2
Ground
+5VDC
Input 3
Input 4
Ground
Figure 5 - Input Connector Pin Assignments (Facing Connector)
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Output Connector Pin Assignments
The Output connector is a double height terminal block. Figures 6 & 7 show the pin assignments.
Figure 6 – Output Connector
Top
Row
Bottom
Row
Ground
Output 8
Output 7
K
Ground
Output 6
Output5
K
Ground
Output 4
Output 3
K
Ground
Output 2
Output 1
K
Figure 7 - Output Connector Pin Assignments (Facing Connector)
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Indicators
Referring to Figure 3 above indicators D1 – D8 indicate the state of output pins 1 – 8 respectively. Polling
of the RS485 connection is indicated by a green LED between connectors P1 and P4. A power on LED is
located between connectors P2 and P3.
Selector Switch S1
Selector switch S1 is a 10 position dip switch. Positions 1 – 8 open or close a path to a 10K ohm pull up
circuit for each input. Position 10 connects a 120 ohm termination resistor between the RS485
communications lines TR+ and TR-. The 120 ohm RS485 termination is important in longer RS485 cable
runs and does no harm on shorter runs.
Dip switch position 9 is unused.
To configure S1 the circuit board must be removed from the enclosure. Figure 8 shows its location on the
circuit board.
Figure 8 - Dip Switch (lower left)
Figure 9 shows a close up detail of the switch. In the example shown in Figure 9 switches 1 – 5 are closed
to provide pull up for inputs 1 – 5. Also note that position 10 is closed to provide RS485 termination.
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Positions 6 – 8 are open so the inputs can be used with analog sensors.
TN0027 – Multifunction I/O Module
Hardware Configuration
TN0027 - 28 August, 2013
Specifications
I/O controller with eight open collector outputs and eight multi-mode inputs rated at 30 volts maximum that can be
individually configured for pulse counting, digital inputs, or analog inputs.
Power and Environmental
Input power – 9 – 24VDC
Operating temperature – minus 30C to plus 70C
Operating humidity – 90% non-condensing
Common Input Specifications



Maximum Input Voltage - 30 volts
Input Logic - Low <1 volt; High >4 volts
Sample Rate - 512 Hz
Pulse Inputs
Minimum Pulse width - 3 msec
Maximum Pulse Count Stored between reads - 32767
Analog Inputs:
Analog Input Measurable Range - 0 - 5 volts
Analog Read Frequency - 20 Hz
Analog Input A/D Conversion - 12 bit with 10 mV offset
Digital Outputs:
Open Collector Output Rating - 30 volts 350 ma, 250 ma with all inputs on
Maximum Update Frequency - 60 Hz
Pulse Width Modulation - 7.8 KHz, 8 bit resolution