SOE - Infi 90 Series INSEM01 | ABB - DCS Center

Time-Synchronization

The sync time information is transmitted every second by the INTKM01 module on the time-sync link. The IMSET01 module receives the time information and uses it to update its internal clock.

IMSED01 Block Diagram

IMSED01 module operations are controlled by a microproces sor (Fig. 2-2). The module also contains devices for the man agement of I/O operations (I/O expander bus control, DI isolation, DI circuits), and microprocessor auxiliary devices (boot EPROM, RAM, machine fault timer, FIFO in and FIFO out).

Microprocessor

The IMSED01 module uses a DSP 2101, provided with an internal memory for program and data storage, a timer and a bidirectional synchronous serial line. DSP 2101 uses an exter nal BOOT EPROM containing the module firmware and an additional external RAM. The module also contains bus and address management circuits. BOOT EPROM This memory is used at power up to load the module program into RAM. RAM The RAM memory is partitioned into two pages of 14 kilowords each. The RAM is used for its external code memory and the buffer containing the DI status changes. FIFO The two FIFO memories are used to transfer data between the controller and the internal microprocessor. FIFO in is used by the controller to send the configuration parameters and the commands to the IMSED01 module. FIFO out is used to trans fer information relative to the digital input acquired in the sequence of events mode from the IMSED01 module to the controller. The size of each FIFO is 512 bytes.

Digital Input Isolation

These DI isolation circuits receive the state of the 16 digital input signals through the P3 connector. The supply voltages of the digital inputs are +24 VDC, +48 VDC, +125 VDC, 120 VAC and they must be supplied in the field or by the termination unit. The 120 VAC supply voltage can be used only for the DI standard mode. The setting of the input voltage is implemented on each channel by means of jumpers. Each channel contains an overvoltage protection circuit and an optocoupler which ensures that the card is totally isolated from the field。

Digital Input Circuits

After the isolators the digital inputs are sent to two distinct cir cuits. The first, known as threshold detection and hysteresis, is used for DI standard mode. The second, known as digital input register, is used for acquisition in sequence of events mode. The digital inputs in DI standard mode have a filter on each input channel. The filter, carried out with RC and a threshold comparator, make it possible to obtain two response times, selectable by a jumper: fast (1.5 milliseconds) and slow (18 mil liseconds). The filtered digital inputs are sent to the I/O expander bus. In the sequence event mode, downstream the optocoupler, in addition to being issued to the filters, the digital inputs are sent to digital input registers, from which they are read by the microprocessor. The states of the digital inputs are displayed by 16 LEDs on the front panel of the module.

I/O Expander Bus Control

These circuits include the control circuit for the accesses from I/O expander bus and the communication circuit and FIFOs between the processor and a controller. The circuits contain the module address (set in the module address switch), and generate the control signals in the various types of access from I/O expander bus.

Machine Fault Timer

The microprocessor continually retriggers the machine fault timer (MFT). If the microprocessor or the firmware fails, the controller goes in fail state. The controller reads this state and stops module operation.

IMSET01 Block Diagram

The IMSET01 module has the same block diagram of the IMSED01 module, with the addition of the time-sync input to the microprocessor block (Fig. 2-3).

Time-Sync Input

The IMSET01 module receives the time-sync link time informa tion from the NTST01 unit transmitted via the RS-485 stan dard. The time-sync input circuits convert the received signals and send them to the RX serial port of the microprocessor. If the NTST01 unit is in fault state or is not connected, the IMSET01 module detects the absence of the NTST01 unit.

NTST01 Termination Unit

The NTST01 termination unit attaches to a field termination panel with two screws and spacers. Figure 2-4 is the NTST01 block diagram. It is a printed board circuit that consists of: 

 • Input circuits. 

 • Output circuits. 

 • Optical isolators. 

 • INTKM01/IMSET01 interface. 

 • Voltage regulators (DC-to-DC converters). 

 • Bypass circuits. The input circuits permit the time information reception, when the NTST01 unit is connected to the IMSET01 module. In the INTKM01 connection, these circuits receive the time informa tion coming from the receiver in IRIG-B time code format. In both cases the time information received is sent to the modules connected through the INTKM01/IMSET01 interface. The output circuits are composed of line drivers used to trans mit the time information on the time-sync link. In the INTKM01 connection, the time information comes from the INTKM01 module through the INTKM01/IMSET01 inter face. In the IMSET01 connection the time information comes from the input circuits. The time information is sent to the P1 con nector using the RS-485 standard. The optical isolators provide isolation between the input circuits, the INTKM01/ IMSET01 interface, and the output circuits. The communication between the NTST01 unit and the INTKM01 and IMSET01 modules is accomplished by RS-485 standard lines, through the connector P2 on the INTKM01/ IMSET01 interface which converts the internal signals into the RS-485 standard. The voltage regulators and DC-to-DC converters generate the 24 VDC, all the output voltages to supply the input circuits, the INTKM01/IMSET01 interface, and the output circuits. All voltages generated by the block are controlled by the power supply control that puts the NTST01 unit in bypass if one of the voltages is absent. The bypass circuits operate when the NTST01 unit is con nected to the IMSET01 module. They permit the connection of the input lines to the output lines present on terminal block TB1. The NTST01 unit is in bypass, when there is no power or the power supply control has detected a fault condition. The NTST01 unit provides an automatic bypass device operat ing in case of fault as a protection-device against: voltage over flow, voltage inversion, temporary short circuit in the transmission circuits, and overvoltage in the transmission and receiving circuits. The output circuits are isolated from the input circuits.