CDT规约解读
? ? ? ?在電力行業(yè)，采集RTU數(shù)據(jù)經(jīng)常會(huì)選擇CDT規(guī)約，而物理鏈路上一般走串口232轉(zhuǎn)485。如果是短距離傳輸，不需要轉(zhuǎn)發(fā)器，傳輸距離長了最好232轉(zhuǎn)485后轉(zhuǎn)光纖再轉(zhuǎn)485轉(zhuǎn)232，防止信號(hào)衰敗丟失。
????? 下面主要介紹CDT規(guī)約。相對(duì)101規(guī)約、102規(guī)約和104規(guī)約，CDT規(guī)約比較簡單。
????? 調(diào)試的時(shí)候可以使用串口調(diào)試工具接收串口報(bào)文，3個(gè)eb 90 開頭的即可確定是CDT規(guī)約。
轉(zhuǎn)：
規(guī)約要點(diǎn)
（1）源地址和目的地址設(shè)為1。
（2）頻率轉(zhuǎn)發(fā)序號(hào)設(shè)置從偶數(shù)開始,通常為2點(diǎn)放到一個(gè)信息字內(nèi),功能碼0x8A, BCD碼發(fā)送。
（3）要求轉(zhuǎn)發(fā)遙測值傳送的是一次值,要配置系數(shù)值。（工程轉(zhuǎn)換或比例縮放）
（4）轉(zhuǎn)發(fā)遙測值帶品質(zhì)描述。
?? 設(shè)置溢出標(biāo)志：額定值小于2047的設(shè)成額定值，大于2047的設(shè)成2047,電壓限值設(shè)成1.2倍額定值。
?? 由于CDT發(fā)送的最大碼值為 -2048 ~ 2047,所以當(dāng)最大值大于2047時(shí)要放縮發(fā)送.
?? 可計(jì)算總加遙測上傳。
（5）遙測轉(zhuǎn)發(fā)序列可設(shè)定:ABA ABA ABC ABA ABA ABC ABA ABA ABC D1 D2 (舉例)
（6）遙測分為重要遙測,次要遙測,一般遙測。YCA32點(diǎn);YCB32點(diǎn);YCC其余點(diǎn)，遙測分配的功能碼共有128個(gè)，最大傳送數(shù)256。D1遙信分配的功能碼共有16個(gè)，最大傳送數(shù)512.
（7）每個(gè)E幀只上送一個(gè)SOE。
（8）華北網(wǎng)調(diào)要求遠(yuǎn)動(dòng)雙通道上送數(shù)據(jù)，保證其主備通道數(shù)據(jù)完全一致。（雙機(jī)并行或單機(jī)雙通道）
（9）事故總信號(hào)放在第一位遙信，即YX1；事故時(shí)為“1”，無事故時(shí)為“0”。總加遙測上送。
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上行信息的優(yōu)先級(jí)排列順序和傳送時(shí)間要求：
l???????? 對(duì)時(shí)的子站時(shí)鐘返回信息插入傳送
l???????? 變位遙信、子站工作狀態(tài)變化信息插入傳送，要求在1s內(nèi)送到主站
l???????? 遙控、升降命令的返送校核信息插入傳送
l???????? 重要遙測安排在A幀傳送，循環(huán)時(shí)間不大于3s
l???????? 次要遙測安排在B幀傳送，循環(huán)時(shí)間一般不大于6s
l???????? 一般遙測安排在C幀傳送，循環(huán)時(shí)間一般不大于20s
l???????? 遙信狀態(tài)信息，包括子站工作狀態(tài)信息，安排在D1幀定時(shí)傳送
l???????? 電能脈沖計(jì)數(shù)值安排在D2幀定時(shí)傳送
l???????? 事項(xiàng)順序記錄安排在E幀以幀插入方式傳送
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下行(主站至子站)命令的優(yōu)先級(jí)排列如下：
l???????? 召喚子站時(shí)鐘，設(shè)置子站時(shí)鐘校正值，設(shè)置子站時(shí)鐘
l???????? 遙控選擇、執(zhí)行、撤消命令，升降選擇、執(zhí)行、撤消命令，設(shè)定命令
l???????? 廣播命令
l???????? 復(fù)歸命令
l???????? D幀傳送的遙信狀態(tài)、電能脈沖計(jì)數(shù)值是慢變化量，以幾分鐘至幾十分鐘循環(huán)傳送。
l???????? E幀傳送的事件順序記錄是隨機(jī)量，同一事件順序記錄應(yīng)分別在三個(gè)E幀內(nèi)重復(fù)傳送。
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幀類別代號(hào)定義表
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下文是一段CDT報(bào)文解讀的例子，讀者可以根據(jù)CDT規(guī)約標(biāo)準(zhǔn)來逐漸理解CDT規(guī)約。
RTU發(fā)送
重要遙測(A幀) 源地址=1 目標(biāo)地址=1 信息字?jǐn)?shù)=32
eb 90 eb 90 eb 90? 同步頭
71 61 20 01 01 11? 控制字
00 00 00 00 00 FF ???01 00 00 00 00 9d ????02 00 00 00 00 3b
03 00 00 00 00 59 ???04 00 00 00 00 70 ????05 00 00 00 00 12
06 00 00 00 00 b4 ???07 00 00 00 00 d6 ????08 00 00 00 00 e6
09 00 00 00 00 84 ???0a 00 00 00 00 22 ????0b 00 00 00 00 40
0c 00 00 00 00 69 ???0d 00 00 00 00 0b ????0e 00 00 00 00 ad
0f 00 00 00 00 cf ????10 00 00 00 00 cd ????11 00 00 00 00 af
12 00 00 00 00 09 ???13 00 00 00 00 6b??? ?14 00 00 00 00 42
15 00 00 00 00 20 ???16 00 00 00 00 86??? ?17 00 00 00 00 e4
18 00 00 00 00 d4 ????19 00 00 00 00 b6 ???1a 00 00 00 00 10
1b 00 00 00 00 72 ???1c 00 00 00 00 5b ????1d 00 00 00 00 39
1e 00 00 00 00 9f ????1f 00 00 00 00 fd??? ??
解讀
eb 90 eb 90 eb 90? 同步頭
71 61 20 01 01 11? 控制字? 61重要遙測 20 32個(gè)信息數(shù) 01 源站， 01 目的站? 11 校驗(yàn)
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00 00 00 00 00 FF? ?
00（信息地址） 00 00 （點(diǎn)號(hào)0，值為0 ）00 00 （點(diǎn)號(hào)1，值為0 ） FF? （校驗(yàn)）
解讀? 01 00 00 00 00 9d? 其他類似
01（信息地址） 00 00 （點(diǎn)號(hào)2，值為0 ）00 00 （點(diǎn)號(hào)3，值為0 ） FF? （校驗(yàn)）
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次要遙測（B幀） 源地址=1 目標(biāo)地址=1 信息字?jǐn)?shù)=32
eb 90 eb 90 eb 90 ?同步頭
71 c2 20 01 01 d4 ?控制字
20 00 00 00 00 9b ???21 00 00 00 00 f9 ????22 00 00 00 00 5f
23 00 00 00 00 3d ???24 00 00 00 00 14 ????25 00 00 00 00 76
26 00 00 00 00 d0 ???27 00 00 00 00 b2 ????28 00 00 00 00 82
29 00 00 0000 e0 ?????2a 00 00 00 00 46??? ?2b 00 00 00 00 24
2c 00 00 00 00 0d ????2d 00 00 00 00 6f ????2e 00 00 00 00 c9
2f 00 00 00 00 ab ???30 00 00 00 00 a9 ?????31 00 00 00 00 cb
32 00 00 00 00 6d ???33 00 00 00 00 0f ?????34 00 00 00 00 26
35 0000 00 00 44 ????36 00 00 00 00 e2 ??????37 00 00 00 00 80
38 00 00 00 00 b0 ???39 00 00 00 00 d2 ??????3a 00 00 00 00 74
3b 00 00 00 00 16 ???3c 00 00 00 00 3f ????3d 00 00 00 00 5d
3e 00 00 00 00 fb ???3f 00 00 00 00 99
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解讀 ：
eb 90 eb 90 eb 90? 同步頭
71 c2 20 01 01 d4? 控制字? c2次要遙測 20 32個(gè)信息數(shù) 01 源站， 01 目的站? d4 校驗(yàn)
信息字解讀同上。
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電能脈沖數(shù)值（D2幀） 源地址=1 目標(biāo)地址=1 信息字?jǐn)?shù)=64
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eb 90 eb 90 eb 90? 71 85 40 01 01 e8 ?
a0 00 00 00 00 0c ??a1 00 00 00 00 6e ??a2 00 00 00 00 c8
a3 00 00 00 00 aa ??a4 00 00 00 00 83 ??a5 00 00 00 00 e1
a6 00 00 00 00 47 ??a7 00 00 00 00 25 ??a8 00 00 00 00 15
a9 00 00 00 00 77? ?aa 00 00 00 00 d1 ??ab 00 00 00 00 b3
ac 00 00 00 00 9a ??ad 00 00 00 00 f8 ???ae 00 00 00 00 5e
af 00 00 00 00 3c ???b0 00 00 00 00 3e ??b1 00 00 00 00 5c
b2 00 00 00 00 fa ???b3 00 00 00 00 98 ??b4 00 00 00 00 b1
b5 00 00 00 00 d3 ??b6 00 00 00 00 75 ??b7 00 00 00 00 17
b8 00 00 00 00 27 ??b9 00 00 00 00 45 ??ba 00 00 00 00 e3
bb 00 00 00 00 81 ??bc 00 00 00 00 a8 ??bd 00 00 00 00 ca
be 00 00 00 00 6c ??bf 00 00 00 00 0e ???c0 00 00 00 00 a0
c1 00 00 00 00 c2?? ?c2 00 00 00 00 64 ??c3 00 00 00 00 06
c4 00 00 00 00 2f ??c5 00 00 00 00 4d ???c6 00 00 00 00 eb
c7 00 00 00 00 89 ??c8 00 00 00 00 b9 ??c9 00 00 00 00 db
ca 00 00 00 00 7d ??cb 00 00 00 00 1f ???cc 00 00 00 00 36
cd 00 00 00 00 54 ??ce 00 00 00 00 f2 ???cf 00 00 00 00 90
d0 00 00 00 00 92 ??d1 00 00 00 00 f0 ??d2 00 00 00 00 56
d3 00 00 00 00 34 ??d4 00 00 00 00 1d ??d5 00 00 00 00 7f
d6 00 00 00 00 d9 ??d7 00 00 00 00 bb ??d8 00 00 00 00 8b
d9 00 00 00 00 e9 ??da 00 00 00 00 4f ??db 00 00 00 00 2d
dc 00 00 00 00 04 ??dd 00 00 00 00 66 ??de 0000 00 00 c0
df 00 00 00 00 a2
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解讀
eb 90 eb 90 eb 90? 同步頭
71 85 40 01 01 e8 ?控制字? 85電能脈沖記數(shù)值 40 64個(gè)信息數(shù) 01 源站， 01 目的站? e8 校驗(yàn)
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a0 00 00 00 00 0c 第0路脈沖 脈沖計(jì)數(shù)值 0，注意計(jì)數(shù)值為32位。
a1 00 00 00 00 6e第1路脈沖 脈沖計(jì)數(shù)值 0，注意計(jì)數(shù)值為32位
其他類似。
總結(jié)
