Interpretation of Terms of MIL-SSTD-1553B Bus Protocol
â— Synchronization (without data words) This command synchronizes the RT (for example, resetting the internal timer, starting a sequence, etc.) and the RT should send the corresponding status word.
â— The send status word instruction shall cause RT to send a status word related to the last valid instruction word before this instruction. The instruction shall not change the status of the status word.
• Transmitter shutdown This instruction (used only for dual redundancy buses) should cause RT to turn off the transmitter connected to the redundancy bus and the RT should not execute the transmitter instructions on the bus from which the instruction was received. In all cases, after this instruction, the RT shall respond in accordance with the specified status word.
â— Disable terminal flag (T/F) This instruction should cause RT to set the terminal flag to logic 0 in the specified status word until another command is issued. The RT should send the specified status word.
â— Cancel the prohibition terminal flag This instruction should cause RT to cancel the above-mentioned prohibition terminal flag. The RT should send the specified status word.
â— Reset Remote Terminal This command is used to reset RT to the power-on initial state. The RT should send its status word first and then reset.
â— Synchronization (with data words) The RT shall receive an instruction word followed by a defined data word. This data word should contain synchronization information for RT. After receiving the instruction and data word, the RT shall send the specified status word.
â— Sending the last status word In addition to the RT receive sending the previous instruction word mode code, this instruction should cause the RT to send its own status word specified, followed by a single containing the 4th to 19th bits of the previous instruction word. Data word. This mode command should not change the status of each RT status word.
â— Status word A status word should be received by a synchronization waveform, remote terminal address, message error bit, test field bit, service request bit, three spare bits, broadcast command reception bit, busy bit, subsystem flag, dynamic bus control Bits, terminal flags, and parity bits. For any optional broadcast operation, the transmission of the status word should be prohibited.
• The ninth bit of the Message Error Bit Status Word is used to indicate that one or more data words associated with an instruction word previously received from the bus controller did not pass the specified RT validity test. This bit should also be set in the event of incorrect data timing, illegal instructions, and incorrect message formats. Logic 1 indicates that there is a message error, and logic 0 indicates no message. All RTs should provide message error bits.
• The tenth bit of the test status bit status word should be reserved for the test bit and always be logic zero. This bit and the tenth bit of the instruction word are logical 1 together, and are used to distinguish whether the amount is an instruction word or a status word. The use of test bits is optional.
• The eleventh bit of the service request status word should be reserved as a service request bit. The use of this bit is optional. If used, this should indicate that the bus controller needs to take predetermined special actions corresponding to the RT or related subsystems. When multiple subsystems connected to a single RT request service request signals, their respective signals should be logically ORed into a single data word to identify the specific subsystem that requested the service. This service request bit only determines the data transfer operation that was used to trigger the exception to occur instead of the cycle. Logic 1 indicates that there is a service request, and logical 0 indicates no service request. If this function is not implemented, this bit should be set to 0.
• The 12th bit of the standby status bit status word is reserved for future use and should not be occupied. These bits should be set to logic 0.
â— When the fifteenth bit of the broadcast instruction reception bit status word is set to logic 1, it indicates that the previous valid instruction word is a broadcast instruction, and logic 0 indicates that it is not a broadcast instruction. This bit should be set to logic 0 if the broadcast command selection method is not used.
â— The 16th bit of the busy bit status word should be reserved as a busy bit. The use of this bit is optional. If used, this should indicate that the RT or subsystem cannot move data into or out of the subsystem as directed by the bus controller. A logic 1 indicates that there is a "busy" state, and a logic 0 indicates that there is no "busy" state. If a busy bit is set in response to a send instruction, RT only sends its status word. If this function is not implemented, this bit should be set to logic 0.
â— The 17th bit of the subsystem flag status word should be reserved as a subsystem flag. The use of this bit is optional. If used, this bit should indicate that the subsystem is in a fault state and the warning bus controller data may be invalid. When the subsystems connected to a single RT request the subsystem flag signals respectively, their respective signals should be logically ORed into a single status word subsystem flag. If logical OR is done, the designer must prepare a separate data word to identify the subsystem that specifically reports. Logic 1 indicates a flag and logic 0 indicates no flag. If not used, this bit should be set to logic 0.
â— Dynamic bus control should be reserved for dynamic bus control when receiving the 18th bit of the bit status word. This bit should apply if RT implements an optional dynamic bus control function. In use, this bit should indicate acceptance or rejection of the proposed dynamic bus control proposal. Logic 1 indicates acceptance of control, and logic 0 indicates rejection of control. If this function is not used, this bit should be set to logic 0.
â— The 19th bit of the terminal flag status word should be reserved for the terminal flag function. The use of this place is optional. If used, this bit is a sign of RT fault status. A logical 1 indicates that there is a fault, and a logical 0 indicates that there is no fault. If this function is not used, this bit should be set to logic 0.
â— The status word resets the bits in the status word other than the address. After the RT has accepted a valid command word, it should be set to logic 0. If the condition that caused some bits in the status word (such as the terminal flag) to be set, after these bits are reset to logic 0, it continues to exist, then the bits in the affected status word should be set again, and then as needed Send on the bus.
â— The bus controller to the remote terminal's transmission bus controller shall issue a receive instruction followed by a specified number of data words. RT shall send back a status word to the controller after the message is verified. Instruction words and data words should be sent in a continuous form without word spacing.
â— The transmission terminal controller of the remote terminal to the bus controller shall send a sending instruction to the RT. After verifying the instruction word, the RT shall send back a status word to the controller, followed by the specified number of data words. Status words and data words should be sent without word space.
• In the absence of data words, the command bus controller shall issue a send instruction to the RT using the method code specified in Table I. The RT should send a status word after verifying the instruction word.
â— Transmission from the bus controller to remote terminals (broadcasting) The bus controller shall issue a receive instruction word, where the RT address field is 11111, followed by the specified number of data words. Instruction words and data words should be sent in a continuous form with no gaps. Each RT with a broadcast selection method shall, after the message is verified, place the broadcast instruction reception bit in the status word as specified, and shall not transmit the status word.
• Inter-message bus controllers should provide a minimum interval of 4.0 microseconds between messages. This time is the time from the middle zero crossing of the last bit of the previous message to the middle zero crossing of the synchronization waveform of an instruction word.
â— The minimum non-response time exceeds the minimum time that the terminal waits for 14.0 microseconds before considering that the specified response has not occurred. This time is the time from the middle zero crossing of the last bit of the last word to the middle zero crossing of the desired status word synchronization waveform.
* Terminal Operations • Verification of words The terminal shall ensure that each character meets the following minimum criteria:
A. The word begins with a valid sync field;
B. Everyone is a valid Manchester II type code;
C. The information field has 16 bits, plus the parity bit;
D. Parity of words is odd.
When a word does not meet the above criteria, the word should be considered invalid.
â— The terminal's failure-safety terminal should include hardware that exceeds the execution time to prevent the transmission of signals exceeding 800 microseconds. This hardware should not prevent the correct transmission in response to instructions. Resetting this time-out function should be completed by receiving a valid command on the bus that has occurred time exceeded.
* Remote Terminals • Operation The remote terminal (RT) should operate in response to valid commands received from the bus controller. When the instruction word satisfies the criteria and the terminal address of the instruction word matches the RT address or if the terminal address is 11111 when the RT is selected by the broadcast, the RT shall acknowledge that the instruction word is valid.
â— Invalid command The remote terminal should not respond to the instruction word that specifies the criteria for operation.
â— Illegal instructions Illegal instructions are valid instructions that are specified by the operation, but those bits in the subaddress/mode field, data word count/mode code field, and T/R bit indicate the mode that was not set in this RT Instruction, subaddress, and word count. It is the responsibility of the bus controller to ensure that no invalid instructions are sent. RT designers have a choice of monitoring illegal instructions. If the RT designed by this selection method detects an illegal command and a normal number of consecutive valid data words defined by an illegal instruction word, the RT shall respond with only one status word, setting the message error bit, instead of Use the received information.
â— Reception of valid data When the remote terminal receives a valid command word and a normal number of consecutive valid data words, or receives a single valid data word related to the mode code, RT applies a status word response. Each of the above data words should meet the above requirements.
â— Invalid data reception Any data word related to a valid reception instruction that verifies an error or transmission continuity error, or any error in the data word count, shall cause the remote terminal to set a message error bit in its status word, and Block the transmission of this status word. If a message error has occurred, the entire message should be considered invalid. The domestic company Chengdu Olimp Technology Co., Ltd. has been engaged in the R&D of the 1553B protocol module for many years, which has been highly recognized by the industry and contributes itself to the development of national defense. .
â— Synchronization (without data words) This command synchronizes the RT (for example, resetting the internal timer, starting a sequence, etc.) and the RT should send the corresponding status word.
â— The send status word instruction shall cause RT to send a status word related to the last valid instruction word before this instruction. The instruction shall not change the status of the status word.
• Transmitter shutdown This instruction (used only for dual redundancy buses) should cause RT to turn off the transmitter connected to the redundancy bus and the RT should not execute the transmitter instructions on the bus from which the instruction was received. In all cases, after this instruction, the RT shall respond in accordance with the specified status word.
â— Disable terminal flag (T/F) This instruction should cause RT to set the terminal flag to logic 0 in the specified status word until another command is issued. The RT should send the specified status word.
â— Cancel the prohibition terminal flag This instruction should cause RT to cancel the above-mentioned prohibition terminal flag. The RT should send the specified status word.
â— Reset Remote Terminal This command is used to reset RT to the power-on initial state. The RT should send its status word first and then reset.
â— Synchronization (with data words) The RT shall receive an instruction word followed by a defined data word. This data word should contain synchronization information for RT. After receiving the instruction and data word, the RT shall send the specified status word.
â— Sending the last status word In addition to the RT receive sending the previous instruction word mode code, this instruction should cause the RT to send its own status word specified, followed by a single containing the 4th to 19th bits of the previous instruction word. Data word. This mode command should not change the status of each RT status word.
â— Status word A status word should be received by a synchronization waveform, remote terminal address, message error bit, test field bit, service request bit, three spare bits, broadcast command reception bit, busy bit, subsystem flag, dynamic bus control Bits, terminal flags, and parity bits. For any optional broadcast operation, the transmission of the status word should be prohibited.
• The ninth bit of the Message Error Bit Status Word is used to indicate that one or more data words associated with an instruction word previously received from the bus controller did not pass the specified RT validity test. This bit should also be set in the event of incorrect data timing, illegal instructions, and incorrect message formats. Logic 1 indicates that there is a message error, and logic 0 indicates no message. All RTs should provide message error bits.
• The tenth bit of the test status bit status word should be reserved for the test bit and always be logic zero. This bit and the tenth bit of the instruction word are logical 1 together, and are used to distinguish whether the amount is an instruction word or a status word. The use of test bits is optional.
• The eleventh bit of the service request status word should be reserved as a service request bit. The use of this bit is optional. If used, this should indicate that the bus controller needs to take predetermined special actions corresponding to the RT or related subsystems. When multiple subsystems connected to a single RT request service request signals, their respective signals should be logically ORed into a single data word to identify the specific subsystem that requested the service. This service request bit only determines the data transfer operation that was used to trigger the exception to occur instead of the cycle. Logic 1 indicates that there is a service request, and logical 0 indicates no service request. If this function is not implemented, this bit should be set to 0.
• The 12th bit of the standby status bit status word is reserved for future use and should not be occupied. These bits should be set to logic 0.
â— When the fifteenth bit of the broadcast instruction reception bit status word is set to logic 1, it indicates that the previous valid instruction word is a broadcast instruction, and logic 0 indicates that it is not a broadcast instruction. This bit should be set to logic 0 if the broadcast command selection method is not used.
â— The 16th bit of the busy bit status word should be reserved as a busy bit. The use of this bit is optional. If used, this should indicate that the RT or subsystem cannot move data into or out of the subsystem as directed by the bus controller. A logic 1 indicates that there is a "busy" state, and a logic 0 indicates that there is no "busy" state. If a busy bit is set in response to a send instruction, RT only sends its status word. If this function is not implemented, this bit should be set to logic 0.
â— The 17th bit of the subsystem flag status word should be reserved as a subsystem flag. The use of this bit is optional. If used, this bit should indicate that the subsystem is in a fault state and the warning bus controller data may be invalid. When the subsystems connected to a single RT request the subsystem flag signals respectively, their respective signals should be logically ORed into a single status word subsystem flag. If logical OR is done, the designer must prepare a separate data word to identify the subsystem that specifically reports. Logic 1 indicates a flag and logic 0 indicates no flag. If not used, this bit should be set to logic 0.
â— Dynamic bus control should be reserved for dynamic bus control when receiving the 18th bit of the bit status word. This bit should apply if RT implements an optional dynamic bus control function. In use, this bit should indicate acceptance or rejection of the proposed dynamic bus control proposal. Logic 1 indicates acceptance of control, and logic 0 indicates rejection of control. If this function is not used, this bit should be set to logic 0.
â— The 19th bit of the terminal flag status word should be reserved for the terminal flag function. The use of this place is optional. If used, this bit is a sign of RT fault status. A logical 1 indicates that there is a fault, and a logical 0 indicates that there is no fault. If this function is not used, this bit should be set to logic 0.
â— The status word resets the bits in the status word other than the address. After the RT has accepted a valid command word, it should be set to logic 0. If the condition that caused some bits in the status word (such as the terminal flag) to be set, after these bits are reset to logic 0, it continues to exist, then the bits in the affected status word should be set again, and then as needed Send on the bus.
â— The bus controller to the remote terminal's transmission bus controller shall issue a receive instruction followed by a specified number of data words. RT shall send back a status word to the controller after the message is verified. Instruction words and data words should be sent in a continuous form without word spacing.
â— The transmission terminal controller of the remote terminal to the bus controller shall send a sending instruction to the RT. After verifying the instruction word, the RT shall send back a status word to the controller, followed by the specified number of data words. Status words and data words should be sent without word space.
• In the absence of data words, the command bus controller shall issue a send instruction to the RT using the method code specified in Table I. The RT should send a status word after verifying the instruction word.
â— Transmission from the bus controller to remote terminals (broadcasting) The bus controller shall issue a receive instruction word, where the RT address field is 11111, followed by the specified number of data words. Instruction words and data words should be sent in a continuous form with no gaps. Each RT with a broadcast selection method shall, after the message is verified, place the broadcast instruction reception bit in the status word as specified, and shall not transmit the status word.
• Inter-message bus controllers should provide a minimum interval of 4.0 microseconds between messages. This time is the time from the middle zero crossing of the last bit of the previous message to the middle zero crossing of the synchronization waveform of an instruction word.
â— The minimum non-response time exceeds the minimum time that the terminal waits for 14.0 microseconds before considering that the specified response has not occurred. This time is the time from the middle zero crossing of the last bit of the last word to the middle zero crossing of the desired status word synchronization waveform.
* Terminal Operations • Verification of words The terminal shall ensure that each character meets the following minimum criteria:
A. The word begins with a valid sync field;
B. Everyone is a valid Manchester II type code;
C. The information field has 16 bits, plus the parity bit;
D. Parity of words is odd.
When a word does not meet the above criteria, the word should be considered invalid.
â— The terminal's failure-safety terminal should include hardware that exceeds the execution time to prevent the transmission of signals exceeding 800 microseconds. This hardware should not prevent the correct transmission in response to instructions. Resetting this time-out function should be completed by receiving a valid command on the bus that has occurred time exceeded.
* Remote Terminals • Operation The remote terminal (RT) should operate in response to valid commands received from the bus controller. When the instruction word satisfies the criteria and the terminal address of the instruction word matches the RT address or if the terminal address is 11111 when the RT is selected by the broadcast, the RT shall acknowledge that the instruction word is valid.
â— Invalid command The remote terminal should not respond to the instruction word that specifies the criteria for operation.
â— Illegal instructions Illegal instructions are valid instructions that are specified by the operation, but those bits in the subaddress/mode field, data word count/mode code field, and T/R bit indicate the mode that was not set in this RT Instruction, subaddress, and word count. It is the responsibility of the bus controller to ensure that no invalid instructions are sent. RT designers have a choice of monitoring illegal instructions. If the RT designed by this selection method detects an illegal command and a normal number of consecutive valid data words defined by an illegal instruction word, the RT shall respond with only one status word, setting the message error bit, instead of Use the received information.
â— Reception of valid data When the remote terminal receives a valid command word and a normal number of consecutive valid data words, or receives a single valid data word related to the mode code, RT applies a status word response. Each of the above data words should meet the above requirements.
â— Invalid data reception Any data word related to a valid reception instruction that verifies an error or transmission continuity error, or any error in the data word count, shall cause the remote terminal to set a message error bit in its status word, and Block the transmission of this status word. If a message error has occurred, the entire message should be considered invalid. The domestic company Chengdu Olimp Technology Co., Ltd. has been engaged in the R&D of the 1553B protocol module for many years, which has been highly recognized by the industry and contributes itself to the development of national defense. .