SM500F
Field mountable paperless recorder
Appendix B – Modbus TCP/Modbus 485
156
IM/SM500F Rev. Z
B.5 Operating Mode Modbus Registers
Tables B.11 to B.13 detail the contents of the Modbus TCP registers accessible while the recorder is in the
operating mode.
Two data types are used:
32-bit single precision floating point data in IEEE format
64-bit double precision floating point data in IEEE format
Note.
When writing to a parameter that occupies more than one register position then all registers
relating to that parameter MUST be written to as part of a multiple register write. If this is not
achieved a NAK exception response is issued. Individual registers can be read without causing an
exception response.
When accessing a parameter that occupies more than one register position, the lowest numbered
register contains the most significant data.
Read Only, single
precision IEEE floating
point number
Analog Input
Modbus Register
A1
0001 and 0002
B1
0003 and 0004
B2
0009 and 0010
C1
0005 and 0006
C2
0011 and 0012
D1
0007 and 0008
D2
0013 and 0014
Table B.11 Analog Inputs
Alarm
Trip Point
Registers
Alarm
Trip Point
Registers
Alarm
Trip Point
Registers
Alarm
Trip Point
Registers
1.1A
0101 and 0102
1.4A
0125 and 0126
2.1A
0133 and 0134
2.4A
0157 and 0158
1.1B
0103 and 0104
1.4B
0127 and 0128
2.1B
0135 and 0136
2.4B
0159 and 0160
1.1C
0105 and 0106
1.4C
0129 and 0130
2.1C
0137 and 0138
2.4C
0161 and 0162
1.1D
0107 and 0108
1.4D
0131 and 0132
2.1D
0139 and 0140
2.4D
0163 and 0164
1.2A
0109 and 0110
1.5A
0165 and 0166
2.2A
0141 and 0142
2.5A
0181 and 0182
1.2B
0111 and 0112
1.5B
0167 and 0168
2.2B
0143 and 0144
2.5B
0182 and 0184
1.2C
0113 and 0114
1.5C
0169 and 0170
2.2C
0145 and 0146
2.5C
0185 and 0186
1.2D
0115 and 0116
1.5D
0171 and 0172
2.2D
0147 and 0148
2.5D
0187 and 0188
1.3A
0117 and 0118
1.6A
0173 and 0174
2.3A
0149 and 0150
2.6A
0189 and 0190
1.3B
0119 and 0120
1.6B
0175 and 0176
2.3B
0151 and 0152
2.6B
0191 and 0192
1.3C
0121 and 0122
1.6C
0177 and 0178
2.3C
0153 and 0154
2.6C
0193 and 0194
1.3D
0123 and 0124
1.6D
0179 and 0180
2.3D
0155 and 0156
2.6D
0195 and 0196
Table B.12 Alarm Trip Levels