JP2556948B2 - Dynamic selection method of modem protocol supporting multiple modem types - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to electronics, and more specifically to signal communication between certain digital signal output devices that communicate with other digital signal devices through a communication medium. Moreover, the present invention relates to any command sent to or expected by a modem during setup, connection, or completion of any communication, which is appropriate for the connected modem. To use the command set,
If any type of modem is connected, it relates to a dynamic selection algorithm utilized by the digital device to determine which type of modem is connected.

[0002]

2. Description of the Related Art When communicating between digital devices through various communication means such as telephone lines and radio waves, it is necessary to use a modem in order to convert digital signals from the devices into modulated signals suitable for transmission media. Devices similar to Applicants' device have traditionally been designed with the same type of modem on all output ports. If another modem type that requires a different command set is used, a different board is inserted into the device to interface with the new modem type. You can connect any type of modem to any given port on a digital device without changing the printed circuit board, and take advantage of the physical applicability of different types of modems when they appear. If it could be done, of course, it would be useful. The obvious solution to this situation is to provide several switch types at each output port of the digital device,
That would be possible. These switches can be set to configuration settings corresponding to command sets for each of several different modems. in this case,
The digital device can inspect the setting status of the switch and use a command suitable for the setting status. However, a technician may not make the correct settings or forget something, and even if the switch settings are correct, pay attention to the possibility of the modem being disabled or the modem being removed. necessary.

The present invention solves this problem by maintaining a list of all modem types used in the storage means of the digital device and the associated command set used for each type. In addition, having a unique initialization command in memory that is unique to each modem type allows that modem to be queried to determine exactly which modem type is connected. The expected response can be continuously examined for each modem type until known. If the output command does not mean a response, or does not mean a predetermined response, the modem may be disabled or disconnected and an appropriate error signal may be generated. it can.

Therefore, it is an object of the present invention to provide an improved interface between a digital device and a modem connected to it, and by providing such an interface, a dynamic modem selection algorithm is used to determine the modem type. To determine the appropriate command to be used with that modem.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A random access unit, or RAU 10, is shown in FIG. 1 with four ports 1-4. Port 1 is connected to modem 12, while ports 2, 3, and 4 are connected to modems 14, 16 and 18, respectively. A transmission line, telephone line, or communication means 20 is connected between the modem 12 and the modem 22, which modems are connected to the computer 24. The modem 14 is connected by a transmission line 26 to a modem 28 and a video terminal 30. Modem 16
The printer 3 via the transmission line 32 and the modem 34.
6 is connected. The modem 18 is only connected to the transmission line and nothing is connected to the other end of this transmission line. Block 10 shows three internal blocks. One is a comparison means, one is a storage means,
The other is a flag means. These blocks are listed because the computer is rarely programmed to perform functions such as compare, store, and flag items.

In FIG. 2, the modem initialization block 40
Is shown with the A input due to a fault or error condition from one of several parts of the flow chart of FIG. This device also enters the modem initialization block 40 when the unit TURN ON. Block 4
The process started at 0 proceeds to block 42. The modem type flag is cleared at block 42 and the pointer is set for the first modem type in the pointer table of FIG. Here, it is a Hayes / AT type modem. The algorithm proceeds to block 44
As shown in both FIG. 4 and block 44, A
Options with T and carriage return (carr
The initialization command sequence is sent as the sum of the image return (CR). As shown in block 46, a 2 second timer is started to allow the command sequence to be sent. This wait state is achieved by decision block 48. Once the command is sent, the algorithm proceeds to block 50 and FIG.
Investigate any response received by the port from the modem 12, etc. A loop is formed between decision block 50 and timeout block 52. If a response is received, then follow the path to decision block 54,
The response is examined to determine if it is a valid response for a Hayes / AT type modem. If it is a valid response, then OK and Carriage Return (CR), as shown in FIG. 4, the algorithm proceeds to block 56 and port 1 is connected to a Hayes / AT modem. Will be flagged. The program then proceeds to the B input in FIG. On the other hand, if a timeout occurs without receiving a response, or decision block 54 determines that the response is not suitable for a Hayes / AT modem, then block 5
A MOTOROLA / EN initialization command sequence is queued, as shown in FIG. This is shown in FIG. 4 as the second modem type. As explained in block 60, the pointer is reset to the MOTOROLA / EN position in the table of FIG. A two second timer is started as indicated at block 62 and the algorithm proceeds to decision block 64.
Once the command is sent, the algorithm proceeds to block 66 and goes to decision block 66 and decision block 6 until a timeout occurs or a response is received.
Move the loop between eight. If a timeout has occurred, it proceeds to block 70. In block 70, M
The port is flagged as an OTOROLA / NON-AUTODIAL modem and proceed to FIG. MOTORO
If a response is received that is not valid for the LA / EN block, as indicated by decision block 72,
Proceed to block 70. However, the response is MOT
If valid for OROLA / EN, in other words, if the response is the colon (:) shown in FIG. 4 as the expected response, then as described in block 74. , The algorithm is MOTOROLA / E
Flag the port as an N modem. The options for the Hayes modem can be sent as part of the initialization code, but for MOTOROLA type modems, these options are sent after the initial command sequence and according to block 76. Then the algorithm proceeds to the input of FIG.

As described below, MOTOROLA
NON-AUTODIAL type modems do not give a return response. As an example of the inventive concept, all commands from RAU10 are MOTOROLA NON-AUT.
If no response is received, assuming it is an ODIAL command, then it is a MO, as shown in FIG.
It will be assumed to be a TOROLA NON-AUTODIAL type command.

As can be seen with reference to FIG. 3, the first block 80 is the entry point to the flow diagram of FIG. 3 and is set to the disconnected state and the DTR (data terminal ready) is set to 0 in block 80. It The flow chart proceeds to decision block 82 where various items are examined. If DSR (data set preparation) is equal to 0, DCD (data carrier detect) is set to 0, and CTS (clear for transmission) is set to 0, the clear error flag is set in block 84. Is set. However, if any one of these items is not set to 0, an error flag is set at block 86 and control is taken to block and establish a given modem at block 4 of FIG.
Return to 0. The set error flag generally indicates that there is no matching modem. From block 84, the algorithm proceeds to block 88. In this block 88,
Data terminal preparation (DTR) is set to 1. If one of the three references in decision block 82 is set to 1, RAU 10 or its associated modem 1
It means that there is a hardware error in either of the 2 and the like. Because at this time, none of these states should be non-zero. In other words,
There is no carrier, no dataset is prepared, and there is no data to send, ie C
This means that TS should be 0. Block 88
As mentioned above, once the data terminal ready flag is set to 1, the program proceeds to decision block 90 to check if there is any pending connection request inside RAU block 10. If not, the program proceeds to decision block 92 to check if the data set ready is set to one. If not, the program returns to decision block 90 and stays in this loop until the data is ready to be sent. If there are pending requests and the data set preparation is set to 1, the program proceeds to block 94.
The pointer is set to the appropriate modem type in the conversion table FIG. 5 determined by the modem type flag in the table of FIG. Then the algorithm is block 96.
And point to the online valid response table determined by the modem type flag. This table is shown in Figure 6.
Explained. The pointer is then set to the telephone number and dialed, as described in block 98. Since the pointer is located in the appropriate translation table, the process can proceed to block 100, as previously shown at block 94. At block 100, the local processor command is translated to match the protocol of the modem for which the connection was established using the translation table described in FIG. The process then proceeds to block 102 where the translated command is queued to port 1, etc. A two second timer is started at block 104 and a loop is formed around decision block 106 until a command is sent. Once the command is sent, the algorithm proceeds to decision block 108 which waits for a response from the port. The process proceeds to timeout decision block 110 and cycles through these two decision blocks until a timeout occurs and returns to modem initialization block 40 of FIG. 2 or a response is received and proceeds to decision block 112. If the response is not valid for the modem type indicated by the pointer in FIG. 4, then return to FIG. 2 to initialize the modem. If the response is valid, decision block 1
Proceed to 14 to check if the response is busy, or there is no dial tone, or if there is an error or abort signal. If these conditions exist, proceed to start the five minute timer in block 116,
Then a decision block 1 forming a timeout loop
Proceed to 18. After the 5 minute timeout has completed, proceed to decision block 90 to check if there are any pending connection requests. Returning again to decision block 114, if a dial tone is present, the error abort flag is not present, and the response is not busy, the process proceeds to block 120 to set the connection state and then to decision block 122 to disconnect. Investigate if the request is pending. If not pending, proceed to decision block 124. If the disconnect request is pending, the process returns to block 80 to set disconnect. On the other hand, if there is no pending disconnection, the method proceeds to block 124 where it is examined whether the data set preparation is set to zero. If not set, block 80, which matches one of the two criteria of decision blocks 122 and 124 and sets a new communication.
It remains in the loop until it returns to.

As mentioned previously, FIG. 4 shows the three types of modem lists used in one embodiment of the present invention, plus the transmission of the first two along with its own unique expected response. With the only command that is done. In one embodiment of the invention, RAU 10 includes a default set of commands,
Since it uses the same expected response as MOTORORAL NON-AUTODIAL, it is not necessary to send a command in the execution indicated by the algorithm. However, a more general solution is to have only one command for every expected modem. At this time, MOTOROLA NON-AUTO
Further investigation of the DIAL modem requires only minimal additions to FIG.

FIG. 5 illustrates two modem types, namely Hay.
A conversion table for various commands such as dial, pause, dial tone wait, and command end for each of es / AT and MOTOROLA / EN, the default commands contained in RAU10 and listed under MOTOROLA / NON-AUTODIAL It is shown in comparison with.

FIG. 6 illustrates various modem responses that can be generated from each of the three listed modem types in FIG. Operation Algorithm The operation appears to be self-explanatory from the tables of FIGS. 2 and 3 and FIG. 1 and further FIGS. When attempting to determine the connected modem type, and when it becomes apparent, the system proceeds to the first modem type in the list of FIG. 4 and sends the only initialization command. If the system gets the expected response for that modem type, a flag is set, as shown in block 56, and the system proceeds further to check for hardware or other errors. If none are found, the software will check if there are any more communications to process, assuming all events are in feasible order. If there is a pending disconnect request when the predetermined communication is completed, or if the data set preparation is set to 0, the system will proceed to decision block 80.
Return to. If the system gets invalid, the system returns to FIG. 2 to reinitialize, and if there is a busy response, the system returns to decision block 90 and proceeds from that point.

In summary, the present invention asks the port to which a modem is to be connected using a single initialization command to ask which type of modem is connected to that port, The present invention relates to the concept of determining whether a connected port is operable or in a non-connected state. It then uses the internally stored table to command the translation table to be used, based on the selection made by the previously established logic, to ensure that any future communication with the modem will be translated appropriately. It can be recognized by the pointer and some other types of display that are set for the response table. In the present invention, if the proper response is not received from the first N-1 modems, ie, the only modem that can be substituted is the last modem on the list,
However, the concept of the present invention is to search all modems on the list when it is desired to use the additional programming space needed to search all modems on the list. Including doing.

In the prior art, all modems connected to the RAU were required to be of the same type, but the concept of the present invention is that if there are different types of commands listed in various tables. If so, each port can be connected to a different modem. Further, according to this inventive concept, the next time an error is detected, the system will automatically reset an internal flag for that port, so that the technician will forget to replace the necessary hardware switch. Nonetheless, it is possible to replace a failed modem with a different type of modem.

Having disclosed certain embodiments of the present invention,
The invention is not to be limited by what has been shown, and should be limited only by the scope of the appended claims.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital device connected to various other digital devices through a modem.

FIG. 2 is a flow chart of a part of an algorithm forming the concept of the present invention.

FIG. 3 is another flow chart used in conjunction with the flow chart of FIG. 2 describing the concepts of the present invention.

FIG. 4 is a diagram showing an initialization command sequence and an expected response.

5 is a diagram showing a modem command conversion table for each modem type shown in FIG. 4;

6 is a modem response table for expected responses from each modem or modem type listed in FIG.

Claims (2)

(57) [Claims] 1. A method for automatically adjusting an outgoing communication protocol for a remotely connected device according to the type of the remotely connected device, comprising: a. Establishing multiple communication protocol commands to communicate with multiple device types, b. Providing the remotely connected device with a first command set compatible with the first device type; c. Decoding a reply signal from the remotely connected device to determine if the remotely connected device is the first device type, d. If it is determined that the remotely connected device is of the first device type, go to step (g); e. Providing the remotely connected device with a second command set compatible with a second device type; f. Decoding a reply signal from the remotely connected device to determine if the remotely connected device is the second device type, g. The method further comprising continuing communication with the remotely connected device using a command set adapted to decode a reply signal. 2. A method for automatically adjusting an outgoing communication protocol sent from a given port to a connecting device according to a response received after sending an initialization command sequence, each of which is properly connected and operating. Generating a list of initialization command sequences that produces a unique response from the modem, setting a pointer to the first modem type in the list, and (a) the actual response to the expected response. Until the first of the matching and (b) the pointer is moved to the last modem type in the list, (c) the initialization command sequence corresponding to the modem indicated by the pointer. Waiting for an expected response determined within a predetermined time by a step of transmitting, and (d) a list and a configurable pointer, If the expected response is not received within the specified time, move the pointer to the next position in the list, and if the pointer does not point to the last modem type in the list, return to step (c), repeat step Flagging the predetermined port according to the modem type indicated by the pointer, and communicating with the remotely connected device using a command set compatible with the modem type indicated by the pointer. Further continuing.