KROHNE H250 M40 EN - Manual (Page 29)

ELECTRICAL CONNECTIONS
4
29
H250 M40
www.krohne.com 11/2012 - 4000640702 MA H250 M40 R02 en
Load for HART ® communication
The maximum load resistance is calculated as follows:
Configuration
The ESK can be configured via HART ® communication. DD (Device Descriptions) for AMS 10x,
AMS 11x and PDM 6.0 as well as a DTM (Device Type Manager) for PACTware™ 3.0.2.28(3.0 SP5),
3.6.0.3(3.6 SP2) and 4.0.0.6 are available for configuration. They can be downloaded free of
charge from our website.
The current flow rate can be transmitted using the integrated HART ® communication. A flow
counter can be configured. Two limit values can be monitored. The limit values are assigned
either to flow values or to the counter overflow.
Self monitoring - Diagnostics
During both start-up and operation, a wide variety of diagnostic functions are performed
cyclically in the ESK4, in order to guarantee function reliability. When an error is detected, a
failure signal (high) is activated (current > 21 mA, typically 22 mA) via the analog output. More
detailed information can also be obtained via HART
® (CMD#48). The failure signal is not activated
in the event of information and warnings.
Diagnostic functions (Monitoring):
• Plausibility of FRAM data
• Plausibility of ROM data
• Working range of internal reference voltages
• Signal detection of the measuring range of the internal sensors
• Temperature compensation of the internal sensors
• Calibration based on the application
• Plausibility of counting value
• Plausibility of physical unit, system and selected unit
INFORMATION!
A load of at least 230 Ohm is required for HART
® communication.
DANGER!
Use a twisted two-core cable to prevent electrical interference from impeding the DC output
signal.
In some cases a shielded cable may be necessary. The cable shield may only be earthed
(grounded) at one place (on the power supply unit).
MA_H250_M40_R02_en_640702_PRT.book Page 29 Wednesday, November 28, 2012 12:23 PM