Detcon 10C - Manual (Page 9)

Model 10C
1.4 RS-485 Modbus™
The 10C Controllers feature Modbus™ compatible communications protocol and are addressable via the
programming menu for multi-point communications. Communication is two wire, half-duplex, with the
Model 10C controller set up as a slave device. A master controller can address a maximum of 255 different
10C Controllers. The actual limit of how many 10C Controllers can be connected to one RS485 Multi-drop
line depends upon desired maximum response time, noisy conditions, cable quality, and length. If a multi-
point system is utilized, each 10C Controller must be set with a unique Modbus™ address. Address settings
are given in hexadecimal, such as: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11, etc. (See
Section 4.5 to set the Modbus™ address.)
The following register list describes the parameters available from 10C controller:
Register #
High Byte Low Byte
40000 Range
40001 Reading
40002 Alarm 1 Set Point
40003 Alarm 2 Set Point
40004 Not Used
40005 Status Bits
40005 Status Bits High Byte:
Bit 15 – Reserved
Bit 14 – Reserved
Bit 13 – Reserved
Bit 12 – Test mode status
Bit 11 – Reserved
Bit 10 – Reserved
Bit 9 – Reserved
Bit 8 – Reserved
40005 Status Bits Low Byte:
Bit 7 – Alarm 2 / 0 – Ascending, 1 – Descending
Bit 6 – Alarm 2 / 0 – Non-latching, 1 – Latching
Bit 5 – Alarm 2 alarm status / 0 – no alarm, 1 – alarm
Bit 4 – Alarm 1 / 0 – Ascending, 1 – Descending
Bit 3 – Alarm 1 / 0 – Non-latching, 1 – Latching
Bit 2 – Alarm 1 alarm status / 0 – no alarm, 1 – alarm
Bit 1 – Fault / 0 – Non-latching, 1 – Latching
Bit 0 – Fault status / 0 – no fault, 1 - fault
1.5 Controller Models
Table 1 provides a list of the available 10C Controller Models, the target gas, the standard Range and Units for
that gas, and the gas formula. Most 10C Controllers can be programmed for a Range other than the standard
Range if needed. (For more information on setting Range, see Section 4.2 Range Set.)
The label on the Model 10 faceplate follows a standard color scheme for identifying the gas type: Yellow =
Solid State H2S, Orange = Combustible Gas, Green = Oxygen and Blue = Electrochemical Toxic (various).
The gas identifier label on the face plate also shows the gas formula and Units: ppm, ppb, or %.
10C Control Module Instruction Manual Rev. 0.B Page 5 of 25