RS-232 Status Feedback Description for the Home Theater Standard 7.1

The Home Theater Standard 7.1 reports its operational status by trans- mitting a block of status data via the RS-232 connector. The block is configured as eighteen 8-bit words. The first and last word always con- tains hexadecimal code 55 to facilitate message framing and synchro- nization. When the data block is sent through an RS-232 port, each

8-bit word transmitted will also have 1 stop bit associated with it. The exact RS-232 protocol settings for both status and Home Theater Standard 7.1 control are as follows:

9600 Baud

8 Data Bits

1 Stop Bit

No Parity

The feedback system is available only through the RS-232 connector. The status can be activated in two ways. The first is to ask for status to be sent by sending the RS-232 command code "STAZ". The second is to enable auto status by sending the RS-232 command code "ASTEZ". Once the auto status command is sent, the Home Theater Standard 7.1 will transmit a status block whenever the status changes. Auto status is disabled by sending the RS-232 command code "ASTDZ". Auto status remains enabled until AC power is removed or turned off. When AC power is reapplied, auto status is disabled.

RS-232 Status Block Descriptions for the Home Theater Standard 7.1

All numeric values described in the following charts are decimal values unless otherwise noted. The description of the eighteen 8-bit words follow.

The values marked Reserved must be ignored during pattern matching.

Word 1: Start of Message

Bit

7

 

6

5

4

3

2

1

0

Description

0

 

1

0

1

0

1

0

1

 

Bit 7 – 0:

Hexadecimal 55

 

 

 

 

 

 

Word 2: General Status I

Bit

7

 

6

 

 

5

 

4

 

3

 

2

 

 

1

 

0

Description

System Mute

User Mute

Zone 2 Mute

 

Current Zone

Input Trigger

 

Zone 2 Only

Zone 2 Power

 

Main Power

 

Bit 7:

System Mute

1

= Internal mute is active

Bit 3:

Input Trigger

1

= 12V input trigger is active

 

Bit 6:

Main Mute

1

= Main mute is active

Bit 2:

Zone 2

Only

1

= Only Zone 2 power is on

 

Bit 5: Zone 2 Mute

1

= Zone 2 mute is active

Bit 1:

Zone 2

Power

1

= Zone 2 power is on

 

Bit 4:

Current Zone

1

= Zone 2 is active

 

Bit 0:

Main Power

1

= Main power is on

 

Krell Home Theater Standard 7.1 Developer’s Reference

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Krell Industries RC-5, RS-232 manual Word 1 Start of Message, Word 2 General Status
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RC-5, RS-232 specifications

Krell Industries, renowned for its high-end audio and video components, has made significant advancements in connectivity protocols, particularly the RS-232 and RC-5 interfaces. These technologies are integral to modern home theater systems and high-fidelity audio setups, enabling seamless communication between devices while ensuring superior performance.

The RS-232 interface, a standard for serial communication, is widely used in professional and consumer electronics. Krell’s implementation of RS-232 allows for robust control of audio and video equipment. It supports bidirectional data transmission, which means that not only can commands be sent to the device, but status can also be communicated back to the controller. This feature is essential for integrated systems where centralized control is desired, enhancing user convenience.

One of the standout characteristics of Krell's RS-232 integration is its compatibility with a variety of control systems, including automation interfaces from major brands. This ensures that users can easily incorporate Krell products into their existing setups without compatibility issues. Additionally, the RS-232 connection supports long cable runs, making it ideal for larger installations, such as those in dedicated home theaters or commercial spaces.

On the other hand, the RC-5 protocol, developed by Philips, is a widely adopted infrared standard that facilitates remote control operations. Krell Industries has embraced this technology to ensure that their equipment is easily controllable using standard remote controls or universal remote systems. RC-5’s simplicity and efficiency in sending commands over infrared make it an excellent choice for consumer applications where ease of use is a priority.

One of the main features of the RC-5 system is its command structure, which allows for a variety of user-defined commands. This flexibility enhances user experience, as it enables customization of device response and control sequences. Moreover, Krell’s products designed with RC-5 support can be effortlessly integrated with home automation systems, allowing users to manage their audio and video components alongside lighting, security, and other connected devices.

In summary, Krell Industries’ incorporation of RS-232 and RC-5 interfaces showcases their commitment to quality and user experience in high-end audio and video products. These technologies facilitate seamless integration, robust control, and customization, making the overall system more versatile and user-friendly. With Krell’s innovative approach, enthusiasts can elevate their audio and video experiences to new heights while enjoying the benefits of modern connectivity solutions.
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