IC693ALG391 - Analog Current Output module

SPECIFICATIONS

Part No.: IC693ALG391
Manufacturer: General Electric
Country of Manufacture: United States of America (USA)
No. of channels: 2
Ext. Supply Voltage Range: 20 to 30 VDC
Update Rate: 5 msec
Max Output Load: 5 mA
Product Type: Analog Current Output module
Availability: In Stock
Series: Mark I and II

Functional Description

IC693ALG391 is an Analog Current Output module developed by GE. It is part of the Mark I and II control system. It is a 2-Channel Analog Current Output module designed for use with the Series 90-30 Programmable Logic Controller (PLC) by General Electric (GE). This module is integral in converting digital data into analog signals, providing essential output capabilities for a wide range of applications.

Features

• Features two output channels, each capable of converting 12-bit binary (digital) data into a corresponding analog current output. Each channel independently handles output data, making it a flexible choice for systems requiring dual analog output signals.
• This module offers a current output range of 0 to 20 mA. The 12-bit resolution enables fine-grained control over the output signal. Each channel receives 12 bits of data, which translates to a 0 to 20 mA current output, with 0 mA corresponding to the lowest binary value and 20 mA corresponding to the highest binary value.
• The module does not use a sign bit in its conversion, so it is strictly for positive current values, with negative data being handled by outputting the lower limit of the current range (4 mA).
• The module is updated during each PLC scan cycle, ensuring that both output channels reflect the latest data. This is achieved through the AQ register, which holds 13 bits of data, with 12 bits used in the conversion process to analog and the remaining bit (the sign bit) being used for checking negative data inputs.
• If the module receives data that would otherwise result in a negative output, the system will limit the current to the 4 mA lower threshold (the minimum range). The module’s software is designed to reject any input values exceeding 32767 to prevent invalid data from affecting the output.

Output Ranges and Resolution

• Output Ranges:
  • 4 mA Range: When the count is 0, it corresponds to 4 mA.
  • 20 mA Range: A count of 32000 maps to 20 mA.
• Resolution: The output resolution is 12 bits, which provides a high level of accuracy and precision. The module’s output current changes incrementally with each input, with each increment of 1000 counts representing a change of 0.5 mA. This ensures fine control over the output current, which is critical in systems requiring high accuracy.

Current and Voltage Output

• The module functions as a current source for both output channels. Each channel’s current output is directly proportional to the digital input data. The module drives the current output to maintain consistency with the data it receives from the PLC.
• For applications requiring voltage output rather than current, a 250-ohm resistor can be used in place of the standard voltage jumper. This converts the output current into a voltage signal that can be easily integrated with other devices in the system. The voltage range output will depend on the selected current output range, providing additional flexibility for users who require either voltage or current signals.

Power Supply and Wiring

• The module requires an isolated +24 VDC power supply provided by the PLC’s main power system. This ensures that the module operates with stable voltage for its internal processing and output generation.
• Additionally, the module has two terminals on its I/O terminal board for user-supplied +24 VDC. This external voltage source acts as a standby power to maintain output values if the internal power supply fails. When the Hold-Last-State option is selected, the user-supplied voltage ensures that the output values are maintained even during power interruptions.
• The user-supplied +24 VDC should be within a range of 21.5 to 26.5 VDC. This ensures that the module can operate as expected, providing stable and accurate output.
• If the voltage is within this range, it is used by the module to support its operation.
• To minimize the effects of electrical noise and signal degradation, high-quality twisted and shielded cables should be used for field wiring. This setup helps reduce electromagnetic interference (EMI) and ensures signal integrity, particularly in environments with high electrical noise.
• Additionally, proper grounding (GND) of the cables should be maintained to further mitigate electrical disturbances.
• The module can be configured to operate without external user-supplied power. Up to three Analog Current Output modules can be connected to the PLC and powered from the PLC’s internal power supply, provided that the total current draw does not exceed the power supply limits.

The WOC team is always available to help you with your Mark I and II requirements. For more information, please contact WOC.

Frequently Asked Questions

What is IC693ALG391?
It is an Analog Current Output module developed by GE under the Mark I and II series.

What are the output ranges of the board?
It provides analog current outputs ranging from 0 to 20 mA. The module has two output ranges 4 mA Range and 20 mA Range.

How is the output resolution defined?
The output resolution is 12 bits. Each increment of 1000 counts represents 0.5 mA of current. The module does not use the sign bit for output conversion.

How does the module handle negative data?
If the board receives negative data, it outputs the minimum current of 4 mA. The software is designed to reject values greater than 32767.