Utilizing the Direct-Digital MODBUS interface for ClearView db – OEM Applications

ClearView db is a modular filter photometer suitable for many OEM applications. By selecting up to six filters ranging from 420nm to 2100nm each with a dedicated detector, system integrators have successfully utilized ClearView db for real-time monitoring of liquids and gasses. Examples include: acid & OH number monitoring, detection of copper in acid baths, hydrogen peroxide vapor sterilization, NO2 gas sterilization, water content of solvent or gasses, or color. Additionally, the ClearView db can monitor up to 2 process locations using either flow cells or direct insertion probes.

Guided Wave provides OEM partners with a detailed MODBUS TCP/IP map and implementation examples. This data enables system integrators to quickly incorporate the ClearView db into their existing projects. MODBUS enables directional communication and remote operational control of the analyzer. Commands include: taking a reference, zero, or background scan; applying a slope and bias correction to the measurement result; and alarms or errors. For example, analyzer faults or off spec process alarms. ClearView db monitor does not require an external computer for configuration and operations, Modbus TCP/IP communication is completely integrated into the system and does not need extra software or hardware from a third party supplier

Ultimately by implementing the OEM ClearView db photometer with MODBUS, critical process monitoring information can be quickly delivered to process engineers and other end-users. Allowing your customers to make informed decisions in real-time.

Interested in learning more about the OEM process for the ClearView db?

Block Diagram of the OEM Clearview db

Understanding MODBUS Bit Fields in the ClearView db

The ClearView db does not implement MODBUS bit commands such as Read Coils, Write Coils or Read Input bits. To reduce computational time, the ClearView db instead employs the use of bit fields in unsigned 16 bit words. The table below displays a partial MODUS map for the ClearView db. A complete MODBUS map is provided to OEM partners.

ClearView db Modbus Address 40003 Read / Write Example

BitNameDescription
0RunThe Run bit is set at power up and should be set at all times except during configuration changes. This bit is cleared when the touch screen configuration menu is accessed and set upon exit from the configuration menu screen. When Run is cleared the analyzer will no longer calculate Transmission, Absorbance, Answers or update Analog Output values.
1Referencing ASetting this bit will cause the analyzer to Reference / Zero Channel A. The bit will auto clear when completed. The Run bit must be set for this command to work properly.
2Referencing BSetting this bit will cause the analyzer to Reference / Zero Channel B. The bit will auto clear when completed. The Run bit must be set for this command to work properly.
3Configuration ActiveThis bit is set by the touch panel when the configuration menus are being accessed and cleared when the configuration screens are exited.
4Program SaveSetting this bit will cause the analyzer to save all of the answer configuration settings currently in RAM into EEProm. This bit will auto clear when completed. The Run bit should be cleared before setting this bit and then set after completion.
5Program LoadSetting this bit will cause the analyzer to load all of the answer configuration settings from EEProm into RAM. This bit will auto clear when completed. The Run bit should be cleared before setting this bit and then set after completion.
6Hardware Save
Factory Use Only
Setting this bit will cause the analyzer to save all of the Factory configuration settings currently in RAM into EEProm. This bit will auto clear when completed. The Run bit should be cleared before setting this bit and then set after completion. Factory settings apply only to installed components that cannot be changed in the field.
7 - 14Not used
15Analog Output TestSetting this bit cause the analyzer to enter Analog Outputs Test mode. This test cycles the 4-20mA outputs continuously 4ma, 12mA and 20mA for several seconds each until cleared.
Posted in Guided Wave News.