Remote device telemetry and communication

1. A method implemented by a control system for communicating with a remote device comprises:

determining a frequency of operation of the remote device;

determining whether the frequency of operation of the remote device varies from a programmed frequency;

determining a frequency scaling factor based on whether the frequency of operation of the remote device varies from a programmed frequency;

generating a frequency shift keying (FSK) signal;

scaling the FSK signal to generate a frequency scaled shift keying (FSSK) signal; and

transmitting the FSSK signal to the remote device, wherein transmitting the FSSK signal to the remote device comprises superimposing the FSSK signal as an alternating current signal on a power signal provided to the remote device via a wireline.

2. The method of claim 1 , wherein determining the frequency of operation of the remote device comprises:

transmitting calibration command message to the remote device;

receiving a response message from the remote device, the response message responsive to the calibration command message; and

determining a time base of the response message.

3. The method of claim 1 , wherein the frequency scaling factor compensates at the control system for variation in the frequency of operation of the remote device from the programmed frequency.

4. The method of claim 3 , wherein the frequency scaling factor compensates at the control system for variation in the frequency of operation of the remote device from the programmed frequency compensated for effects of environmental or operating temperature on the frequency of operation of the remote device.

5. The method of claim 1 , wherein scaling the FSK signal to generate the FSSK signal comprises shifting mark and space frequencies by a same percentage as a variance in the frequency of operation of the remote device from the programmed frequency.

6. The method of claim 1 , further comprising shaping the FSSK signal prior to transmitting the FSSK signal to the remote device.

7. The method of claim 6 , wherein shaping the FSSK signal comprises varying an amplitude of the FSSK signal at a transition boundary of the FSSK signal for a predetermined number of marks of the FSSK signal.

8. The method of claim 7 , wherein shaping the FSSK signal reduces an amount of signal loss of the FSSK signal resulting from capacitance of a wireline via which the control system communicates with the remote device.

9. The method of claim 1 , wherein the FSSK signal comprises a command for the remote device to toggle a switch state of a switch blocking the control system from communicating with a device downstream from the remote device on a wireline coupling the control system, the remote device, and the downstream device.

10. A control system, comprising:

a microcontroller including a memory; and

executable code stored as firmware in the memory that, when executed by the microcontroller, configures the microcontroller to:

generate a frequency shift keying (FSK) signal including a command for a remote device;

condition the FSK signal according to operating characteristics of the remote device and characteristics of a communication channel coupling the control system to the remote device to generate a conditioned FSK signal;

transmit the conditioned FSK signal to the remote device via the communication channel;

determine a time base of a message received from the remote device;

determine whether the time base of the message received from the remote device varies from a time base of the control system; and

scale the FSK signal to generate the conditioned FSK signal as a frequency scaled shift keying (FSSK) signal based on a variance between the time base of the message received from the remote device and the time base of the control system.

11. The control system of claim 10 , wherein scaling the FSK signal to generate the FSSK signal comprises shifting mark and space frequencies by a same percentage as a variance in the frequency of operation of the remote device from the programmed frequency.

12. The control system of claim 10 , wherein the executable code further configures the microcontroller to vary an amplitude of the conditioned FSK signal at a transition boundary of the conditioned FSK signal for a predetermined number of marks of the conditioned FSK signal.

13. The control system of claim 10 , wherein the executable code further configures the microcontroller to shape the FSK signal to generate the conditioned FSK signal.

14. The control system of claim 13 , wherein shaping the FSK signal comprises varying an amplitude of the FSK signal at a transition boundary of the FSK signal for a predetermined number of marks of the FSK signal to generate the conditioned FSK signal.

15. A control system, comprising:

a microcontroller including a memory; and

executable code stored as firmware in the memory that, when executed by the microcontroller, configures the microcontroller to:

generate a frequency shift keying (FSK) signal including a command for a remote device;

condition the FSK signal according to operating characteristics of the remote device and characteristics of a communication channel coupling the control system to the remote device to generate a conditioned FSK signal; and

transmit the conditioned FSK signal to the remote device via the communication channel, wherein environmental conditions surrounding the remote device modify a time base of communication of the remote device, and wherein condition the FSK signal according to the operating characteristics of the remote device synchronizes a time base of communication of the control system to time base of communication of the remote device.

16. The control system of claim 15 , wherein the communication channel introduces error into communications between the control system and the remote device by attenuating the communications, and wherein conditioning the FSK signal according to the characteristics of the communication channel reduces the errors introduced into the communications.

17. The control system of claim 15 , wherein the executable code further configures the microcontroller to receive a response message from the remote device via the communication channel, wherein the response message is a Manchester encoded message.

18. The control system of claim 17 , wherein the Manchester encoded message comprises pre-emphasis configured to reduce errors introduced into communications between the control system and the remote device resulting from the communication channel attenuating the communications.