Welcome to the CT-BOX Command Reference Manual
The CT-BOX Measuring System
The CT-BOX by ELS Instruments is a stand-alone digital measuring system designed to measure DC and AC currents with high accuracy, wide bandwidth, high precision and extremely high stability.
The system is developed to be used with the ELS Instruments CT-series current-output DC current transformers (referred to as DCCT in this manual), allowing high-performance measurements of currents up to 1000 A. The device integrates temperature-stabilized components (a burden resistor, signal conditioning networks and a precision 24-bit ADC) in order to keep the temperature dependence lower than 1 ppm/K. The digital section interfaced to the ADC performs a calibrated measurement, drastically reducing the non-ideal behaviour and providing very high accuracy.
The ADC sampling frequency is fixed at 100 kHz (100 ksps), which allows the acquisition of high-frequency components and fast current transients. The output data frequency can be reduced through software commands (TS in OSC mode, FREQ in DLOG mode, DMM:FREQ and DMM:NOP in DMM mode); in that case an averaging of the sampled data is performed, which both reduces the required transmission data rate and reduces high-frequency noise, increasing the signal-to-noise ratio.
CT-BOX Versions
The CT-BOX unit is available in the following versions, depending on the maximum current measuring range:
Product Code |
Ordering Code |
Description |
|---|---|---|
CT-BOX-100 |
WCTBOX100XAA |
100 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
CT-BOX-150 |
WCTBOX150XAA |
150 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
CT-BOX-200 |
WCTBOX200XAA |
200 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
CT-BOX-300 |
WCTBOX300XAA |
300 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
CT-BOX-400 |
WCTBOX400XAA |
400 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
CT-BOX-600 |
WCTBOX600XAA |
600 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
CT-BOX-1000 |
WCTBOX1000XA |
1000 A Current Transducer Digital Box with Local Display and Ethernet, USB, RS-232 interfaces |
Note
The command set documented here is common to the whole CT-BOX family. The full-scale current depends on the connected DCCT, which can be identified with the DCCT command. When the primary conductor is wound more than once through the DCCT, the full-scale current is divided by the number of turns set with the PTURNS command.
Scope of this Manual
This Command Reference Manual is aligned with CT-BOX firmware ≥ 3.1.0 and covers:
the communication interfaces (Ethernet TCP/IP, UDP, USB 2.0 and RS-232), the ASCII command syntax, the three modes of operation (OSC, DLOG and DMM) and the corresponding data representations;
the full command set, grouped by the mode(s) of operation in which each command can be used;
the structure of the internal Status and Error registers;
the error codes list.
Note
For mechanical, electrical and installation information (front/rear panel layout, LED indicators, connectors, DIP-switches, power supply, mounting brackets, firmware upgrade procedure, technical specifications and mechanical dimensions) please refer to the CT-BOX User’s Manual.
The plug-and-play GUI acquisition package CT-BOX Viewer, which allows controlling, configuring and acquiring data from multiple units over different interfaces, is described in its own software guide.