Detcon DM-600IS - Manual (Page 34)

DM-600IS
DM-600IS Instruction Manual Rev 1.5.9 Page 30 of 37
however, absolutely critical that changes to gas/range set-up of the Universal Transmitter be consistent with
the gas type and range of the Intrinsically Safe Sensor Head that it is connected to.
NOTE: If the Universal Transmitter is changed for gas type and range, it must be consistent
with the Intrinsically Safe sensor head it is mated with.
If the Universal Transmitter needs to be changed for gas type and range follow this procedure. First, unplug
the transmitter temporarily and then plug it back in. While the message “Universal Transmitter” appears, take
the program magnet and swipe it over magnet PGM1. This will reveal the set-up options for gas range and gas
type.
Swipe over PGM1to advance through the options for gas range which include: 1, 2, 3....10 ppm
10, 15, 20...100 ppm
100, 200, 300...1000 ppm
1000, 2000, 3000
10,000 ppm
When the correct range is displayed, hold magnet over PGM1 for 3 seconds to accept the selection.
Next is your selection for the gas type. In this set-up you will enter the alpha-numeric characters of the gas
type. Reference the list on page 3 for correct symbols. There is space for the chemical formula up to six
characters. Use GM1 and PGM2 swipes to advance through the alphabet and numbers 0-9 selection (there is a
blank space after 9). When the correct alphanumeric character is highlighted, hold the magnet over PGM1 for
3 seconds to lock it in. This moves you to the next blank and the procedure is repeated until the chemical
formula is completed. After the 6th character is locked in the transmitter will proceed to normal operation.
NOTE 1: If the gas symbol has more than 6 characters, the symbol can be replaced by an
abbreviated version of the target gas name such as TOL or TOLUEN for Toluene which has
the symbol C6H5CH3. For Epichlorohydrin (symbol C3H5OCL) you can substitute the name
EPI or EPICHL etc.
NOTE 2: When the Universal Transmitter is re-initialized and a new gas and range is entered,
all of the previous customer settings for alarm levels and span gas value are reset to their
default levels. These must be re-programmed back to the customer specific settings
14.0 RS-485 PROTOCOL
Detcon MicroSafe™ toxic gas sensors feature Modbus™ compatible communications protocol and are
addressable via rotary dip switches for multi-point communications. Other protocols are available. Contact the
Detcon factory for specific protocol requirements. Communication is two wire, half duplex 485, 9600 baud, 8
data bits, 1 stop bit, no parity, with the sensor set up as a slave device. A master controller up to 4000 feet
away can theoretically poll up to 256 different sensors. This number may not be realistic in harsh
environments where noise and/or wiring conditions would make it impractical to place so many devices on the
same pair of wires. If a multi-point system is being utilized, each sensor should be set for a different address.
Typical address settings are: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11, etc.
In most instances, RS-485 ID numbers are factory set or set during installation before commissioning. If
required, the RS-485 ID number can be set via rotary dip switches located on the preamp circuit board.
However, any change to the RS-485 ID number would require the sensor housing to be opened, thus