1. A method comprising a sending device performing steps of:
maintaining a protocol register containing a first and second protocol;
using the first protocol, and without knowing in advance whether a peer device is using the first protocol, attempting delivery of a message to the peer device;
determining that the message was not successfully received by the peer device, thereby indicating that the peer device is using a protocol inconsistent with the first protocol; and
responsive to determining the message was not successfully received by the peer device, retrieving the second protocol from the protocol register; and without knowing in advance whether the peer device is using the second protocol, attempting delivery of a message from the sending device to the peer device using the second protocol;
wherein the step of maintaining a protocol register comprises:
storing, in a first register of the sending device, a current protocol;
storing, in a second register of the sending device, a previous protocol; and
upon the sending device receiving a new protocol,
in the first register, replacing the current protocol with the new protocol, the new protocol defining the first protocol and the current protocol defining a former current protocol;
in the second register, replacing the previous protocol with the former current protocol, the former current protocol defining the second protocol.
2. The method of claim 1, wherein the step of maintaining a protocol register comprises:
storing, in a first register of the sending device, a current protocol; and
upon the sending device receiving a new protocol,
in the first register, replacing the current protocol with the new protocol, the new protocol defining the first protocol and the current protocol defining a former current protocol;
in a second register, storing the former current protocol, the former current protocol defining the second protocol.
3. The method of claim 1, wherein the step of determining comprises:
determining that a response is not received from the peer device within a designated time period after sending the message.
4. The method of claim 1, wherein the step of determining comprises:
receiving a response from the peer device including indicia of confusion of the peer device.
5. The method of claim 1, wherein the first protocol comprises a current protocol and the second protocol comprises a previous protocol of the sending device.
6. A method comprising a receiving device performing steps of:
maintaining a protocol register containing a first and second protocol associated with the receiving device;
receiving a message from a peer device;
without knowing in advance a protocol used by the peer device, unsuccessfully attempting to process the message using the first protocol; and
responsive to unsuccessfully attempting to process the message using the first protocol, retrieving the second protocol from the protocol register; and attempting to process the message using the second protocol;
wherein the step of maintaining a protocol register comprises:
storing, in a first register of the receiving device, a current protocol;
storing, in a second register of the receiving device, a previous protocol; and
upon the receiving device receiving a new protocol,
in the first register, replacing the current protocol with the new protocol, the new protocol defining the first protocol and the current protocol defining a former current protocol;
in the second register, replacing the previous protocol with the former current protocol, the former current protocol defining the second protocol.
7. The method of claim 6, wherein the step of maintaining a protocol register comprises:
storing, in a first register of the receiving device, a current protocol; and
upon the receiving device receiving a new protocol,
in the first register, replacing the current protocol with the new protocol, the new protocol defining the first protocol and the current protocol defining a former current protocol;
in a second register, storing the former current protocol, the former current protocol defining the second protocol.
8. The method of claim 6 further comprising:
unsuccessfully attempting to process the message using the second protocol; and
responsive to unsuccessfully attempting to process the message using the second protocol, sending a message to the peer device including indicia of confusion.
9. The method of claim 6, wherein the first protocol comprises a current protocol and the second protocol comprises a previous protocol of the receiving device.
10. In a communication system including at least a first and second device adapted for communication using a common protocol, the first and second devices each maintaining protocol registers containing a first and second protocol and each being subject to protocol upgrades at different times causing a protocol inconsistency, a method comprising:
upon either of the first and second devices receiving a new protocol, replacing the first protocol with the new protocol, the new protocol defining the current protocol; and replacing the second protocol with the first protocol, the first protocol defining the previous protocol;
sending, from the first device to the second device, a message using a current protocol of the first device without knowing in advance whether the second device is using the current protocol of the first device;
without knowing in advance the protocol used by the first device, unsuccessfully attempting, by the second device, to process the message using a current protocol of the second device;
responsive to the second device unsuccessfully attempting to process the message using the current protocol of the second device, attempting, by the second device, to process the message using a previous protocol of the second device.
11. The method of claim 10, further comprising:
determining, by the first device, that the second device is unable to process the message sent using the current protocol of the first device; and
sending, from the first device to the second device, a message using a previous protocol of the first device.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A high pressure discharge lamp comprising an arc tube; a starter including a ferroelectric ceramic capacitor element with non-linear characteristics and a semiconductor switching element, the capacitor element and the switching element being connected in parallel to the arc tube; an outer tube glass bulb containing the arc tube and the starter; a glass stem for sealing the outer tube glass bulb; and a base positioned at an end portion of the outer tube glass bulb on the glass stem side, wherein a pulse stopping thermally-actuated switch is connected in series to the ferroelectric ceramic capacitor element and is operated to OFF due to heating by a heating resistor in a non-lighted state of the lamp.
2. The high pressure discharge lamp according to claim 1, further comprising a starting circuit opening thermally-actuated switch for maintaining the starter in an OFF operation state at the time when the arc tube is lit, wherein a recovery time of the pulse stopping thermally-actuated switch at the time of restarting the lamp is shorter than a recovery time of the starter circuit opening thermally-actuated switch.
3. The high pressure discharge lamp according to claim 1, wherein the heating resistor is connected in parallel to the pulse stopping thermally-actuated switch and the ferroelectric ceramic capacitor element, and a bypass resistor is connected in parallel to the pulse stopping thermally-actuated switch.
4. The high pressure discharge lamp according to claim 1, wherein the outer tube glass bulb is evacuated, and in the outer tube glass bulb, a leaking filament coil connected in series to the ferroelectric ceramic capacitor and an electrode positioned adjacent to the leaking filament coil are provided so as to conduct an arc discharge between the coil and the electrode.
5. The high pressure discharge lamp according to claim 2, wherein a ceramic substrate is positioned between the arc tube and the glass stem in such a manner that the ceramic substrate is substantially perpendicular to a tube axis of the arc tube, and on the glass stem side of the ceramic substrate, the ferroelectric ceramic capacitor element, the pulse stopping thermally-actuated switch and the heating resistor therefor, and a semiconductor switching element are positioned, and on the arc tube side of the ceramic substrate, the starting circuit opening thermally-actuated switch is positioned.
6. The high pressure discharge lamp according to claim 5, wherein the pulse stopping thermally-actuated switch is positioned on the surface of the ceramic substrate on the glass stem side, and a thickness of the ceramic substrate is set to be not more than 2.0 mm.
7. The high pressure discharge lamp according to claim 1, wherein the pulse stopping thermally-actuated switch is positioned in parallel to the heating resistor, and a resistance of the heating resistor is set in a range of 20 k to 40 k, a power of the heating resistor is set in a range of 0.25 W to 0.5 W, and a distance between the pulse stopping thermally-actuated switch and the heating resistor is set to be not more than 2.0 mm.
8. The high pressure discharge lamp according to claim 7, wherein a tip portion of the pulse stopping thermally-actuated switch is positioned in contact with the heating resistor.
9. The high pressure discharge lamp according to claim 5, wherein the ferroelectric ceramic capacitor is placed substantially in parallel to the surface of the ceramic substrate on the glass stem side, and a distance with the ceramic substrate is set to be not less than 0.5 mm.
10. The high pressure discharge lamp according to claim 5, wherein the semiconductor switching element is positioned outside the outer tube glass bulb and inside the base.
11. The high pressure discharge lamp according to claim 10, wherein in the glass stem, one lead wire connected to one end of the semiconductor switching element and two lead wires connected to a power source are sealed, and a sealing portion of the three lead wires in the glass stem has a cross section of a triangular shape, and the three lead wires are sealed respectively in corners of the triangular shape.