Adapting Systel PLC modem embedded in the IDC2000 to other protocols

The following provides a brief summary of the PLC modem and the possibility of its adaptation to customized protocols:

• The carrier frequency can be increased up to 200 kHz changing two or three coefficients of the programmable frequency dividers.
• The DALI protocol or others may be used instead of Systel's PLC-Link Communication Protocol using suitable software taking into account the fact that the data rate for a 200KHz carrier will be not more than 4000 bit/sec and of course for 100KHz 2000 bit/sec.
• The signal synchronization can be performed not only using zero-cross, as in the PLC-Link implementation, but using preamble as well. The message duration will increase in this case. In this context you can enhance the zero cross detection by taking advantage of the Digital PLL (DPPL) module embedded in the IDC2000. See following specifications:

DPLL Testing Report

Lock-In (Phase Frequency Detector)
Proportional Gain = 1/4
Integration Gain = 1/32
Initial Center Frequency = 55 Hz
Locking Range : 40Hz to 80Hz
Optimal gains are : 1/4 Proportional, 1/32 Integral
Locking Time : 0.3 Seconds

Phase Shift Step Tests

Gains		Time Constant
Proportional	Integral
1/8	1/128	0.7 Sec
1/16	1/512	1.5 Sec
1/32	1/2048	3 sec
1/64	1/8192	6 Sec

Tracking Jitter: approx. 10uS