I/O Module Guide

Introduction

The HMC2000 and HMC4000 HMI + PLC Series supports the following I/O expansion modules. These modules provide digital and/or analog I/O (inputs and outputs) for an electrical control system. All of the I/O Modules are CE and UL Certified.

I/O Expansion Module Overview

Each I/O terminal is labeled for easy identification on the modules. ‘COM’ is the common ground terminal. A terminal with an ‘X’ followed by a number is an input terminal and a terminal with a ‘Y’ followed by a number is an output terminal. The number refers to the position associated with each terminal on the I/O module.

When a project is created in MAPware-7000, bit/register memory addresses are assigned for each terminal on the expansion module. MAPware-7000 provides the option to allow the software to do this automatically. In this case, it will assign memory addresses according to the position and expansion slot in which the I/O module is located.

In addition, many of the I/O modules have a two-pin connector that is used to connect a voltage source (usually +24VDC). This voltage source drives the output terminals of the I/O modules.

Installing I/O Modules

The expansion modules for the HMC2000 and HMC4000 base units attach onto the back of the unit via expansion slots and are secured with a Phillips screw on the top-right and bottom-left corners of the module. The 4.3” screen supports one expansion module. The 7” screen supports up to three modules, while the 10.1” unit supports up to five modules. Modules connected to the 4.3” unit are attached horizontally to the rear housing, while the 7” and 10.1” units allow for vertical mounting of the modules to the rear housing.

Common Terms and Definitions

This section defines some common terms used to describe various types of inputs and outputs. The terms explained below are generic descriptions. Be sure to consult the datasheet for the specific requirements when installing and wiring a module.

Digital Inputs and Outputs

Digital inputs provide physical connections and interpretations of input devices using discrete signals. The input is represented in the PLC input registers as a 1 for the on state and 0 for the off state. Each digital input terminal is associated with an internal Input Coil (X) in the tag database of the HMC. Similarly, each digital output terminal is associated with an Output Coil (Y).

Analog Inputs and Outputs

Analog inputs provide physical connections and interpretations of input devices using analog signals. The input range depends on the type of input device. Configure analog inputs to work with current or voltage sources. Each analog input terminal is associated with an internal Input Register (XW) in the tag database of the HMC IO module. Similarly, each analog output terminal is associated with an Output Register (YW).

Sinking versus Sourcing

These terms refer to the type of digital inputs or outputs used. A sourcing I/O provides a voltage source, and a sinking I/O provides a ground. Any module that is not bidirectional (meaning current can go in either direction) requires that the circuit conduct current in a specific direction. In order to have current flow, each I/O terminal on the expansion module must have a return path or a signal ground connection. In most modules, multiple I/O terminals share the signal ground connection.

For a sourcing module, the current flows out of the expansion module terminal and into the common (signal ground) terminal. The term source indicates the terminal on the expansion module provides the current to the switch contact or load. For a sinking module, the current flows into the expansion module terminal and out of the common terminal on the I/O module. The term sink indicates the terminal takes in the current from the switch contact or load.

Note: Arrow indicates current flow direction

Digital Outputs (PNP or NPN type)

The output terminals of a digital I/O module use an optically isolated PNP or NPN transistor to energize the connected load. PNP/NPN outputs are faster than relay outputs but can only work with low current DC loads (typically 500mA max per terminal). PNP modules are sourcing modules, and NPN modules are sinking modules.

Note: the above diagrams show that a PNP output is ‘sourcing’ current and the NPN output is ‘sinking’ current.

Digital Outputs (Relay type)

The output terminals of a relay-type digital module typically control loads that require an AC power source.

Use a Relay Output module to connect a DC load that requires more current than the maximum available when using a PNP or NPN output. For AC loads, each relay output contact can handle up to 230VAC with a 2A load per contact. For DC loads, each relay output contact can handle a 2A load per contact for up to 30VDC.

Analog Voltage

Analog voltage inputs can measure DC voltage ranges of 0-5 and 0 to 10 volts. With analog inputs, the analog module writes a data value to the assigned register (XW) based upon the measured DC voltage at the input. Analog outputs can provide 0 to 5VDC and 0 to 10 VDC with a minimum resistance of 1000 ohms depending upon the value in the assigned register (YW). Input resolution is 16-bits and Output resolution is 12-bits.

Analog Current

Analog current inputs can measure DC current ranges from 0 to 20mA and 4 to 20mA. With analog inputs, the analog module writes a data value to the assigned register (XW) based upon the measured DC current at the input. The analog outputs can provide 0 to 20mA and 4 to 20mA. Analog outputs can deliver a DC current of up to 20mA to a load with a maximum resistance of 500 ohms based upon the data value in the assigned register (YW). Input resolution is 16-bits and Output resolution is 12-bits.

Configuring High-speed Counters

Maple Systems’ HMC modules have built-in High-Speed counters that link directly to specific inputs and outputs. Specific registers and bits are predefined for setup and control of these counters. No logic is required to run the counters, other than logic that may be used for configuration and control.

Two inputs on the module are used as the Triggers for the High-Speed counters, and two outputs are used as the Done bits. The inputs support a maximum speed of 200 KHz.

The following bits and registers are associated with a High-Speed counter:

Reference the tables below when configuring each HSC Configuration Register:

HSC Configuration Register Bit table

Specific High-Speed Counter Registers

The registers and I/O associated with the High-Speed Counter can be found below.

Note: nn is the slot in which the module is installed (slot 1 is 01, slot 2 02, etc.)

For example, a module installed in Slot 3 has the following assignments:

Pulse Width Modulation (PWM) Outputs

Maple Systems’ HMC3000 I/O modules have built-in Pulse Width Modulation functionality. Specific registers and bits are predefined for setup and control of these functions. No logic is required to run the PWM, other than logic that may be used to configure and control them.

There are four modes of PWM: Normal, CW/CCW, Pulse/Direction and Fixed Pulse. Use the information below to configure the desired PWM output mode.

Note: For each table below, nn is the slot in which the module is installed (slot 1 is 01, slot 2 02, etc.)

Normal PWM

The frequency must be the same for channel 1 and channel 2, but the Duty Cycle is independently adjustable for each channel. Duty Cycle can be adjusted while the output is running. The valid range is 0 to 100%, but the effective range will vary depending on the device being controlled. The frequency can be adjusted while running (place a 2 in the Config register). The Channel 1 and Channel 2 outputs can be enabled and disabled independently.

CW/CCW (Clockwise/Counter Clockwise)

When the frequency is positive, the output signal is generated on Channel 1, and Channel 2 is not used. When the frequency value is negative, the output signal is generated on Channel 2, and Channel 1 is not used. The frequency can be adjusted while running (place a 4 in the Config register instead of 3), and the Duty Cycle is fixed at 50%.

Pulse/Direction

The output signal is generated on Channel 1. If the frequency value is positive, Channel 2 is held low. If the frequency value is negative, Channel 2 is held high. The frequency can be adjusted while running (place an 8 in the configuration register), and the Duty Cycle is fixed at 50%.

Fixed Pulse Mode

The output signal is generated on Channel 1. The frequency ramps up from the minimum frequency to the maximum frequency in the interval specified by acceleration time. The output signal is generated until the specified number of pulses has been sent. As the number of pulses approaches the specified count, the frequency ramps down from the maximum frequency to the minimum frequency in the interval specified by the deceleration time. When the specified number of pulses is reached, the output signal stops but remains enabled. The Duty Cycle is fixed at 50%.