firepagingbasics

MARITIMES SCANNING SITE

FIRE PAGING BASICS

(WITH PARTICULAR REFERENCE TO HALIFAX REGIONAL FIRE)

LAST UPDATED MAY 23, 2009

For specific CAP codes for HR Fire stations see this page, and come back here to determine actual tones.

Please note that this is not a technical outline as I am certainly no expert on this topic. Like you I have heard many times the two tone fire pages that obviously vary between different fire stations. Pagers for a particular station are programmed to respond and open squelch only for the pair of tones assigned to that station, and additionally to one other pair that may be used for the whole system or for a particular zone made up of several stations. In the Halifax Regional Fire Service there are tones for each station as well as for the zones, but not for the system as a whole.

The set of tones programmed is defined or labeled by a "CAP code", with CAP standing for Channel Access Protocol. There are various systems in existence however I will at this time only speak of the system in use in HRM, which may be referred to as the General Encoding Method which has a 3 digit CAP code.

In this particular system the first digit of the code indicates which tone group column the two tones come from. For example the CAP code for Station 40 in Dutch Settlement is 638. This means that its two tones will both come from Tone Group 6. The middle digit is 3, so that the first tone is 1217.8 Hz, with the second tone being 1395 Hz.

In the HRM system there are a few stations paired, such as 21 and 22, due to having the same body of volunteers but other than in these circumstances no two stations in HRM have the same tones, even though there are great distances between one end of HRM and the other. Pagers are also, like other receivers, tuned to a radio frequency (not to be confused with the tone frequency). HRM pagers only listen to one pager frequency only, so that volunteers away from their community will not necessarily hear the pages, but presumably they would not be available in any event to respond.

Tone Group

Tone Number

Code

Freq

Code

Freq

Code

Freq

Code

Freq

Code

Freq

Code

Freq

Code

Freq

Code

Freq

111

349.0

121

600.9

138

288.5

141

339.6

151

584.8

191

1153.4

170

1472.9

200*

1930.2

112

368.5

122

634.5

108

296.5

142

358.6

152

617.4

192

1185.2

171

1513.5

201*

1989.0

113

389.0

123

669.9

139

304.7

143

378.6

153

651.9

193

1217.8

172

1555.2

202*

2043.8

114

410.8

124

707.3

109

313.0

144

399.8

154

688.3

194

1251.4

173

1598.0

203*

2094.5

115

433.7

125

746.8

160

953.7

145

422.1

155

726.8

195

1285.8

174

1642.0

204*

2155.6

116

457.9

126

788.5

130

979.9

146

445.7

156

767.4

196

1321.2

175

1687.2

205*

2212.2

117

483.5

127

832.5

161

1006.9

147

470.5

157

810.2

197

1357.6

176*

1733.7

206

2271.7

118

510.5

128

879.0

131

1034.7

148

496.8

158

855.5

198

1395.0

177*

1781.5

207

2334.6

119

539.0

129

928.1

162

1063.2

149

524.6

159

903.2

199

1433.4

178*

1830.5

208

2401.0

110

330.5

120

569.1

189

1092.4

140

321.7

150

553.9

190

1122.5

179*

1881.0

209

2468.2

Note that in this relatively simple system there is no provision for pairing tones from different columns, which in other systems is possible with a very large number of combinations possilble. The next step up and still referred to as the General Encoding Method would not define tone columns but rather two tone columns. See the chart below. In this system, the 638 CAP code mentioned above would translate as being from combination 6, with the first tone coming from column 2 (see above chart) and the second tone coming from Group 1. This would translate as Tone 3 from Group (Column) 2 which is 669.9, followed by Tone 8 from Group 1, which is 510.5. Note again that HRM fire does not use this system.

First Digit of Cap Code	Tone Group for first tone	Tone Group for second tone
1	1	1
2	2	2
3	1	2
4	4	4
5	5	5
6	2	1
7	4	5
8	5	4
9	2	4
0	4	2
A	3	3

There are progressively more complex methods, using for example, CAP codes consisting of a letter and four numbers. I am not at this time writing of these as they are not in use in the area, and just another step removed from what we have here. In addition one might expect that there are other entirely different systems also out there, not using these tones or not using tones at all.

Area pages: In the HRM Fire system there are area or zone pages to call or announce to volunteers and stations throughout a wider area. These are done in the same way as the regular pages, with the paging units responding to both sets of tones.

HRM Fire: Core area pages vs Rural pages: In the rural areas consisting entirely or almost entirely of volunteers, the page goes out to the individual firefighters. In the core area where the entire complement is made up of career firefighters the page is directed to the station itself. In the suburban areas there is a substantial mix of career and volunteer firefighters and therefore in those cases there is a page directed to the station itself and when deemed necessary, a different set of tones directed to the individual volunteers. I do not mean to imply that each volunteer has his or her own unique tone pair, but rather that he or she has a personal pager, with all the volunteers for that station having pagers configured identically.