2A-40.RS-232 Interface

HYDRA

Service Manual

description of the External Trigger operation may be found in the "External Trigger Input Circuits" section.

The RS-232 interface is composed of connector A1J4, RS-232 Driver/Receiver A1U13, and the serial communication hardware in Microprocessor A1U1.

The serial communication transmit signal (A1U1-80) goes to the RS-232 driver (A1U13- 14), where it is inverted and level shifted so that the RS-232 transmit signal transitions between approximately +5.0 and -5.0V dc. When the instrument is not transmitting, the driver output (TP13;A1U13-3) is approximately -5.0V dc. The RS-232 receive signal from A1J4 goes to the RS-232 receiver A1U13-4, which inverts and level shifts the signal so that the input to the serial communication hardware transitions between 0 and +5.0V dc. When nothing is being transmitted to the instrument, the receiver output (TP12;A1U13-13) is +5.0V dc.

Data Terminal Ready (DTR) and Request To Send (RTS) are modem control signals controlled by the Microprocessor. When the instrument is powered up, the Microprocessor initially sets DTR and RTS false by setting A1U1-61 and A1U1-79 high, which results in the RS-232 driver outputs (A1U13-7 and A1U13-5 respectively) going to -5.0V dc. When the instrument has initialized the RS-232 interface and is ready to receive and transmit, A1U1-61 and A1U1-79 will go low, resulting in the RS-232 DTR and RTS signals going to +5.0V dc. The RS-232 DTR and RTS signals will remain at +5.0V dc until the instrument is powered down except for a short period of time when the user changes RS-232 communication parameters from the front panel of the instrument.

Clear To Send (CTS) and Data Set Ready (DSR) are modem control inputs from the attached RS-232 equipment. Of these signals, only CTS is used when CTS flow control is enabled when CTS is turned on via the RS-232 communication setup menu. The CTS modem control signal from A1J4 goes to the RS-232 receiver A1U13-6, which inverts and level shifts the signal so that the input to the Microprocessor (A1U1-51) transitions between 0 and +5.0V dc. When the instrument is cleared to send characters to the RS-

232interface, the receiver output (A1U13-11) is +5.0V dc. If the RS-232 CTS signal is not driven by the attached RS-232 equipment, the receiver output (A1U13-11) is near 0V dc.

2A-41.Option Interface

The interconnection to the option slot is implemented by J1 on the Main PCA. This connector (A1J1) routes the outguard logic power supply (VCC and GND), eight bits of the data bus (D<8> through D<15>), RDU*, WRU*, OCLK, RESET*, OPTE*, and the lower three bits of the address bus to the hardware installed in the option slot. This connector also routes an interrupt signal (OINT*) from the option hardware to the IRQ1* input of the Microprocessor (A1U1-97). The OPTE*, RDU*, and WRU* signals pass through series resistors that are necessary to ensure that the instrument meets EMI/EMC performance requirements.

An option sense signal from the installed option allows the Microprocessor to detect whether or not option hardware is installed. Currently there is no optional hardware available for this instrument.

2A-18

2635A, 2625A specifications

The Fluke 2625A is a sophisticated data logger designed for a wide range of industrial and laboratory applications. This versatile instrument excels in capturing and monitoring temperature and voltage measurements with precision and reliability. One of its standout features is its ability to record data from various sensors, making it ideal for environments where comprehensive data acquisition is critical.

Equipped with a large LCD display, the Fluke 2625A provides clear and user-friendly access to real-time measurement data. Its graphical interface allows users to visualize trends and monitor readings easily, which significantly enhances usability. The device supports a variety of input types and can connect to thermocouples, RTDs, and other sensors, offering great flexibility for various measurement tasks.

The Fluke 2625A employs advanced measurement technologies that ensure accuracy in data logging. With a high sampling rate, it captures fast-changing signals while maintaining data integrity. The device features a built-in memory that allows for extensive logging, accommodating long-term monitoring tasks without requiring constant oversight. Users can set it to log data at specified intervals, offering customizable solutions for different monitoring needs.

Another significant characteristic of the Fluke 2625A is its robust communication capabilities. The device supports USB and RS-232 interfaces for easy connectivity with computers and other devices, making data transfer and analysis seamless. This feature is especially beneficial for users who need to compile or analyze large sets of data quickly.

Furthermore, the Fluke 2625A is designed with durability in mind. Its rugged construction makes it suitable for challenging environments, including those with high levels of vibration, dust, or moisture. This reliability ensures that the device can withstand the rigors of fieldwork while still delivering accurate measurements.

In summary, the Fluke 2625A is a powerful data logger that combines versatility, accuracy, and reliability. Its user-friendly interface, advanced measurement technologies, and robust design make it an essential tool for professionals in various industries, from manufacturing and HVAC to research and development. Whether monitoring temperature changes in a laboratory or assessing voltage levels in an industrial setting, the Fluke 2625A stands out as a trusted solution for effective data logging and analysis.

Fluke 2635A, 2625A service manual 2A-40.RS-232 Interface

Models: 2635A 2625A

HYDRA