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FT Output: The function’s FT (fault) output can provide an output to optional logic that can verify successful completion of the Communications Request. The FT output can have these states:

FT Output Truth Table

Enable Input Status

Does an Error Exist?

FT output

 

 

 

Active

No

Low

Active

Yes

High

Not active

No execution

Low

The FT output is set High if:

￿The specified target address is not present (for example, specifying Rack 1 when the system only uses Rack 0).

￿The specified task number is not valid for the device.

￿Data length is set to 0.

The FT output can either be connected to another device, such as a set coil, or can be left open.

Operation of the Communications Request

The figure below illustrates the flow of information between the PLC CPU and the

PROFIBUS Slave module:

PLC CPU

Ladder

program

COMMREQ

CPU

memory

Data

Status word

PLC

Backplane

Command

Requested data

Status bits

PROFIBUS Slave

Module

Firmware

instructions

On-board memory

PROFIBUS

network

to Master

Figure 4-2. Operation of the PROFIBUS Communications Request

A Communications Request is initiated when a COMMREQ ladder instruction is activated during the PLC scan. At this time, a command from the PLC via the Communications Request is sent to the PROFIBUS Master module (PBM).

At the conclusion of every request, the PLC CPU reports the status of the request to the Status Word, which is a location in PLC memory that is designated by the Status Word Pointer in the Command Block.

In Figure 4-2, the PBM is shown in the CPU rack and communications occur over the PLC backplane. If the PBM is located in an expansion or remote rack, the commands and data are sent over the CPU rack’s backplane, through the expansion or remote cable to the rack containing the PBM, and across that rack’s backplane to the PBM.

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Series 90™-30 PROFIBUS Slave Module User's Manual – August 2004

GFK-2193A

Page 21
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GE GFK-2193A user manual Operation of the Communications Request, Plc

GFK-2193A specifications

The GE GFK-2193A is a versatile and powerful programmable logic controller (PLC) designed for industrial automation applications. With its robust construction and advanced features, the GFK-2193A is ideal for industries that demand high reliability and flexibility in their control systems.

One of the standout features of the GE GFK-2193A is its processing power. It is equipped with a high-speed CPU that can handle complex tasks and large volumes of data efficiently. This allows for real-time decision-making and control, making it suitable for critical applications where timing and accuracy are paramount. The processing speed is complemented by a multitasking capability, enabling the controller to manage multiple processes simultaneously without a drop in performance.

The GFK-2193A also boasts an extensive range of input and output options. It supports a variety of digital and analog I/O modules, allowing for seamless integration with different sensors, actuators, and devices. This flexibility makes it easy to customize the system according to specific operational needs, whether it's for small-scale automation or extensive industrial setups.

In terms of communication capabilities, the GE GFK-2193A includes support for multiple industrial communication protocols. This includes Ethernet, Modbus, and Profibus, among others, ensuring compatibility with a wide array of devices and systems. The controller's ability to communicate effectively helps facilitate data exchange, enabling better coordination and monitoring across different components of an automation system.

Another significant feature of the GE GFK-2193A is its programming environment. It utilizes the popular Ladder Logic programming language, which is widely regarded for its ease of use and efficiency. Additionally, the controller supports other programming languages, like Function Block Diagram and Structured Text, providing users with the flexibility to choose the most suitable method for their application.

The durability of the GFK-2193A is another remarkable characteristic. Designed to withstand harsh industrial environments, it features robust housing and components, making it resistant to dust, moisture, and temperature fluctuations. This ensures long-lasting performance with minimal maintenance needs, enhancing overall operational efficiency.

In summary, the GE GFK-2193A is a comprehensive solution for industrial automation that combines processing power, flexibility in I/O configurations, advanced communication capabilities, and a user-friendly programming environment. Its robust construction ensures reliability even in challenging conditions, making it a trusted choice for industries looking to enhance their automation processes.