Detcon CXT-DM - Manual (Page 36)

Model CXT-DM
write (function code 06) to register 8202 with the number of seconds the network should go into low power
mode. During low power mode, there can be no access to any device on the network so changes in sensor
readings will not be updated. Once a non-zero value is written to this register on all transceivers, they will
begin counting down until the Update Rate register reaches zero, at which time all transceivers should be
active again and ready for network communication. The controller will monitor the update rate time
remaining by accessing Update Rate register on the RXT-320 (or equivalent) that it is attached to it. The
Modbus™ interface remains active, only the wireless network is placed in a low power state. The value of this
register can be between 0 and 65535 which allows a maximum low power time of 18.2 hours. Removal of
power will reset Update Rate to 0 and the transceiver will be active again.
4.2.2.4 Register – Control
The CXT transceiver control register is generally unused and should not be written to normally. Using the
control register, the CXT can be reset and Modbus™ exceptions can be enabled. Each bit in the control
register can control a particular function and should be read first then modify the bits needed and written back.
The default state of the register is 0. All reserved bits should always be set to a 0 when writing. The listing
below shows the bit assignments.
Bit 15:
Reserved (set to 0)
Bit 14: Reserved (set to 0)
Bit 13 – 12: Reserved (set to 0)
Bit 11: Modbus Exceptions Enabled
Bit 10 – 08: Reserved (set to 0)
Bit 07: Reset the microcontroller and wireless radio
Bit 06: Reset the microcontroller
Bit 05 – 00: Reserved (set to 0)
4.2.2.5 Register – Status
This register contains status of the CXT transceiver and some of the bits have already been covered in the
battery description. These default to 0 upon reset. The bit assignment and description are given below.
Bit 15 – 08:
Reserved (set to 0)
Bit 07: Reserved (set to 0)
Bit 06: Reserved (set to 1)
Bit 05: I2C Fault on last read of Battery Status
Bit 04: Battery Detected
Bit 03: Reserved (set to 0)
Bit 02: Reserved (set to 1)
Bit 01: Reserved (set to 0)
Bit 00: Reserved (set to 0)
4.2.2.6 Register – Timestamp
Three registers are utilized to maintain a timestamp that increments on the microcontroller after power up.
These are all set to 0 upon power up or a microcontroller reset. The first two registers 8208 and 8209 are
internally combined into a single 32 bit register and incremented each second. The last register 8210
maintains the millisecond count and will count from 0 to 999 and start over again.
CXT-DM Instruction Manual Rev. 1.6 Page 32 of 52