Busy And Delayed-Response; Long Messages; Non-Volatile Memory; Table D-14. Command Response Times - MSA Ultima X Series Installation & Maintenance Instructions Manual

• Program ROM
• Configuration storage EEPROM
• Sensor communications
• Data sheet integrity
• Internal communications.
This self-test takes about 10 seconds. During self-test, following power-
up or reset, the analog output is set to 3.75 mA and the device does not
respond to HART commands.
During self-test run in background mode, the analog output updates
continuously and the device responds normally to HART commands.
Continuous self-testing is part of the normal device operation. The same
checks are made, but over a longer period between measurement
function cycles.

Table D-14. Command Response Times

Minimum 20 ms
Typical 50 ms
Maximum 100 ms *
* During self-test following a power up reset or reset command, the device may take up
to 10 sec to respond.

Busy and Delayed-Response

The transmitter may respond with "busy" status if a further command is
received while self-test or certain command functions are underway.
Delayed-response is not used.

Long Messages

The largest data field used is in the response to Command 21: 34 bytes
including the two status bytes.

Non-Volatile Memory

EEPROM is used to hold the device's configuration parameters. Both
the main board and sensor module contain EEPROM devices. New
data is written to this memory on execution of certain write commands,
during calibration operations and during normal operation.
D-33