Welch Allyn SureTemp PlusModule - User Manual - Manual (Page 16)

Serial Communications Interface SureTemp Plus Module OEM Implementation
16 Confidential Welch Allyn OEM Technologies
Table 2 depicts typical power requirements of the SureTemp Plus module and probe.
Table 2. Power Requirements
Serial Communications Interface
The SureTemp Plus board is a command-driven slave device capable of communicating with a
host system over an asynchronous serial communication line. The host system can set the
module to asynchronous mode, and can cause the temperature cycle to start by removing the
probe from the well. The SureTemp module sends data packets without additional intervention by
the host system.
The host must initiate all other communication with the SureTemp module. See Section 8 for
details describing the serial communications protocol.
Asynchronous Operation
Although the module is a slave device, it can be configured easily to send unsolicited
temperature packets to the host. The serial protocol offers an asynchronous command that
allows the module to send unsolicited temperature packets to begin when the probe is removed
from the well. The packets continue until the probe is returned to the well, or when the module
times out.
Figure 2. State Diagram: Monitor
Operating
Voltage
Operating Current
nonheating
Operating Current
heating (max)
Sleep Current Time to Ready
State
3.3 V 5.2 mA 127 mA 16 µ A 700 mS
3.6 V 5.7 mA 139 mA 17 µ A 500 mS
4.0 V 6.4 mA 155 mA 20 µ A 200 mS
4.5 V 7.3 mA 174 mA 22 µ A 100 mS
5.0 V 8.3 mA 194 mA 25 µ A < 100 mS
Probe pulled;
Start Predict
Algorithm ran 6 cycles;
Active = 1
(Algorithm Status = Final) & Active;
Display the temperature
Final X Idle
FINAL
FINAL_OVER_TEMP
FINAL_UNDER_TEMP
Display Monitor Complete Temperature.
Do not show result; indicate over-temperature.
Do not show result; indicate under-temperature.
Final states: