DCS

CDCSS or Digital Code Squelch (DCS) is a further development of the continuous tone coded squelch system (see What is CTCSS?) but which uses a slow speed binary data stream passed as sub-audible data along with the transmission. Motorola calls this Digital Private Line (DPL). It consists of a 23-bit telegram sent repeatedly on the channel at 134 bits per second along with the voice transmission. This allows for over 100 possible fleet codes to be used. This gives it an advantage over the CTCSS tones in that there are more possible codes to use; however, it does use more bandwidth and can be affected by voice tones below 300 Hz if not properly filtered by the radio circuitry. Below is a chart of the DCS codes:

6	50	125	174	255	343	445	526	703
7	51	131	205	261	346	446	532	712
15	53	132	212	263	351	452	546	723
17	54	134	214	265	356	454	565	731
21	65	141	223	266	364	455	606	732
23	71	143	225	271	365	462	612	734
25	72	145	226	274	371	464	624	743
26	73	152	243	306	411	465	627	754
31	74	155	244	311	412	466	631
32	114	156	245	315	413	503	632
36	115	162	246	325	423	506	654
43	116	165	251	331	431	516	662
47	122	172	252	332	432	523	664

--Lou Maag 14:32, 3 Jan 2005 (EST)