Contents

Revision and copyright information
Table of contents
1. Introduction
2. Specifications
- 2.1 General
- 2.2 Terminal specifications (output mode)
- 2.3 Terminal specifications (input mode)
- 2.4 Pulse counting specifications
3. Installation
- 3.1 Power considerations
- 3.2 Terminal connections
- 3.3 Address selection switches
4. Programming the data logger
- 4.1 General principles
- 4.2 SDMIO16() instruction
- 4.3 SDMCD16AC() instruction
- 4.4 SDMSpeed() instruction
- 4.5 Command codes for the SDMIO16() instruction
Appendix A. General principles of pulse and frequency measurements
- A.1 Introduction
- A.2 Frequency and duty cycle measurement range
- A.3 Resolution of frequency measurements
- A.4 Resolution of duty cycle measurements
- A.5 Debounce filtering
- A.6 Using the I/O line to trigger code to run on a data logger
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Campbell Scientific SDM-IO16A Product Manual

Campbell Scientific SDM-IO16A Peripheral manual cover

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Campbell Scientific SDM-IO16A Peripheral Specification

The Campbell Scientific SDM-IO16A is a versatile, high-performance I/O peripheral designed to expand the digital and pulse-counting capabilities of compatible data loggers. It provides 16 configurable digital input/output channels, allowing for flexible interfacing with various sensors and devices. Each channel can be individually set as an input or an output, with inputs capable of reading high and low logic levels and outputs capable of sourcing or sinking up to 100 mA at 5 VDC.

The SDM-IO16A communicates with the data logger using the Synchronous Device for Measurement (SDM) protocol, enabling high-speed data transfer and precise control. It supports a maximum cable length of 20 meters between the data logger and the device, ensuring reliable connectivity across various setups. The module is housed in a rugged, weather-resistant enclosure suitable for both indoor and outdoor installations, offering durability in harsh environmental conditions.

Power consumption is efficient, with the device drawing minimal current in both active and quiescent states, making it ideal for remote applications where power supply is limited. The SDM-IO16A is compatible with a wide range of Campbell Scientific data loggers, including the CR6, CR1000X, and CR3000, providing seamless integration within existing systems.

This peripheral is particularly useful in applications requiring multiple digital inputs or outputs, such as monitoring and controlling equipment in meteorological, hydrological, or industrial automation systems. Its robust design and flexible configuration options make the SDM-IO16A a reliable choice for expanding the functionality of data acquisition systems in various demanding environments.

Campbell Scientific SDM-IO16A Peripheral F.A.Q.

How do I connect the SDM-IO16A to a datalogger?

To connect the SDM-IO16A to a datalogger, use the SDM cables provided. Connect the SDM, G, and 12V terminals on the peripheral to the corresponding terminals on the datalogger. Ensure that the datalogger is powered off during the connection process.

What should I do if the SDM-IO16A is not responding to commands?

If the SDM-IO16A is not responding, first check all physical connections. Verify that the device is powered and that the datalogger is configured correctly. Ensure that the SDM address matches on both the peripheral and the datalogger.

How can I test the individual channels on the SDM-IO16A?

To test individual channels, you can manually toggle each channel using the datalogger’s program. Use the ‘SDMIO16A’ instruction in the CRBasic Editor to control and monitor the states of the channels.

What is the procedure for updating the firmware on the SDM-IO16A?

Currently, the SDM-IO16A does not support firmware updates in-field. If you suspect a firmware issue, contact Campbell Scientific support for guidance on servicing the device.

Can the SDM-IO16A be used with any datalogger?

The SDM-IO16A is compatible with most Campbell Scientific dataloggers that support the SDM protocol. Make sure to consult the datalogger’s manual to confirm compatibility.

What is the maximum cable length when connecting the SDM-IO16A to a datalogger?

The maximum recommended cable length for connecting the SDM-IO16A to a datalogger is 20 meters. Longer cables may introduce communication issues due to signal degradation.

How can I troubleshoot communication errors between the SDM-IO16A and a datalogger?

To troubleshoot communication errors, ensure that all cables are securely connected and free from damage. Check the SDM address settings and confirm they match on both devices. Also, verify the power supply and datalogger configuration settings.

What maintenance is required for the SDM-IO16A?

The SDM-IO16A requires minimal maintenance. Regularly inspect the connections for corrosion or wear and ensure that the device is kept in a clean, dry environment. Periodically verify the operation of all channels as part of routine system checks.

How do I configure the SDM address for the SDM-IO16A?

The SDM address for the SDM-IO16A can be configured using the DIP switches located on the device. Refer to the user manual for specific DIP switch settings to achieve the desired address.

What should I consider when using the SDM-IO16A in a high-noise environment?

In high-noise environments, use shielded cables and ensure proper grounding of the system to minimize interference. Place the SDM-IO16A away from large electrical machinery and other sources of EMI.