Elgas EDT 101, Руководство пользователя

Страница: 24 / 40

24
4.4 Discrete outputs map
Discrete outputs (coils) can be set by the Force single coil (05h) command. Discrete outputs
address space is accessible only for writing. Reading is not supported.
Physically, the transducer does not have any discrete outputs. Discrete outputs address space
is implemented to allow access to several functions. Forcing a particular discrete output into
ON state starts the assigned function (starts a single measurement, for example).
4.4.1 Overview of the discrete outputs map
Modbus coil numbers shown in the text are in the 0 xxxx format which follow the Modicon
protocol specification for data items addressing. The actual coil address sent in the Modbus
message frame is the coil number shown in the text minus 1.
The following table shows the discrete outputs map of the transducer. Individual functions are
described in the subsequent paragraphs.
Coil no. Coil / Function name
0001 Reset
0002 Write EEPROM
0003 Read EEPROM
0004 Stop measurement
0005 Start single measurement
0006 Start continuous measurement
0017 Unlock user configuration section
0018 Unlock service configuration section
0025 Change user password
0026 Change service password
4.4.2 Reset
Forcing the Master reset coil ON performs a software reset of the transducer. This is similar
to shutting off the power and then reapplying power. The Master reset takes approximately
20 milliseconds to complete. The force master reset coil ON query is not responded.
4.4.3 Write EEPROM
Forcing the Write EEPROM coil ON writes copy of the registers 40003 to 40066 into EEPROM
memory. The registers 40003 to 40066 hold the transducer’s configuration which is recalled
after power-up or by function Read EEPROM. Write cycle takes 10 ms to complete. Any query
received during this time is responded with Exception response code 06 – Slave device busy.
4.4.4 Read EEPROM
Forcing the Read EEPROM coil ON recalls transducer’s configuration from the EEPROM
memory and stores it into registers 40003 to 40066. When the data stored in EEPROM are
corrupted (internally generated checksum does not match the stored value), bit 15 (EEPROM
error) in the Status register is set to indicate possible malfunction of the transducer.