HTP 7350P-629 - Manual (Page 18)

18
The table below lists temperature to hexadecimal conversions.
Setpoint Hex Setpoint Hex Setpoint Hex Setpoint Hex
68 12 101 2A 134 42 167 5A
69 13 102 2B 135 43 168 5B
70 14 103 2C 136 44 169 5C
71 14 104 2C 137 44 170 5D
72 15 105 2D 138 45 171 5D
73 16 106 2E 139 46 172 5E
74 17 107 2F 140 47 173 5F
Setpoint Hex Setpoint Hex Setpoint Hex Setpoint Hex
75 17 108 2F 141 47 174 5F
76 18 109 30 142 48 175 60
77 19 110 31 143 49 176 61
78 19 111 32 144 4A 177 62
79 1A 112 32 145 4A 178 62
80 1B 113 33 146 4B 179 63
81 1C 114 34 147 4C 180 64
82 1C 115 34 148 4C
83 1D 116 35 149 4D
84 1E 117 36 150 4E
85 1F 118 37 151 4F MODBUS Register 40004 Setpoint Conversion Table
86 1F 119 37 152 4F
87 20 120 38 153 50
88 21 121 39 154 51
89 21 122 3A 155 52
90 22 123 3A 156 52
91 23 124 3B 157 53
92 24 125 3C 158 54
93 24 126 3C 159 54
94 25 127 3D 160 55
95 26 128 3E 161 56
96 27 129 3F 162 57
97 27 130 3F 163 57
98 28 131 40 164 58
99 29 132 41 165 59
100 2A 133 42 166 5A
Temperature
The Modbus adapter passes temperature data to the appliance in degrees Fahrenheit. Also, to accommodate decimal places, the
decimal value must be divided by 10. The data sent over the Modbus is passed as an unsigned 16 bit integer. This poses no problem
unless the data becomes negative, such as temperatures below zero. In this case, the compliment has to be calculated as follows:
Temperature to be sent over Modbus = -22
o F. First multiply by 10. -22 X 10 = -220. Calculate compliment 65536-220 = 65316.
Decimal = 65316. Hex = FF24. Binary = 1111111100100100.
To read the outdoor temperature from the appliance, do the opposite. Read register 40006 and get 65316. Since this value is greater
than 32767, the temperature is negative. To calculate the negative value: 65536
– 65316 = 220, then 220/10 = 22. 22 X -1 = -22 o F.
For example:
Outdoor temperature from remote sensor on BAS system = 80.5
o
F.
DECIMAL HEX
805 325
Table 20
Outdoor temperature from remote sensor on BAS system = -25 o F. Data that needs to be transmitted is -25 X 10 = -250. 65536-
250=65286