IS200STTCH1A - Simplex Thermocouple Input Terminal Board

Functional Description

IS200STTCH1A is a Simplex Thermocouple Input Terminal Board manufactured and designed by General Electric as part of the Mark VIe series used in GE Distributed Control Systems. A small terminal board made for DIN-rail or flat mounting is the Simplex Thermocouple Input (STTC) terminal board. The board links to the PTCC thermocouple processor board or to the YTCC pack on the Mark VIeS SIS and has 12 thermocouple inputs. The smaller TBTC board's built-in signal conditioning and cold junction reference are the same as those on the smaller board. Two types of high-density Euro-Block type terminal blocks are available, and they are affixed to the board. For system diagnostics, the processor uses an onboard ID chip to identify the board.

Installation

The sheet metal carrier that holds the STTC and a plastic insulator is mounted on a DIN rail. A sheet metal component that bolts onto a panel holds the STTC and insulator in place. The standard #18 AWG wires are used to directly connect thermocouples to the terminal block. There are 42 fixed or removable terminals on the Euro-block type terminal block. Two types of Euro-Block terminal blocks are available as follows:

• Terminal board STTCH1 and STTCS1 has a permanently mounted terminal block with 42 terminals.
• Terminal board STTCH2 and STTCS2 has a right-angle header accepting a range of commercially available plugged terminal blocks, with a total of 42 terminals.

Operation

The following diagram shows the STTC's connection to the I/O board or pack that houses the A/D converter. The cold junction (CJ) reference on the terminal board is excited by the I/O pack or board. Connector JA1 receives all 12 thermocouple signals, the CJ signal, and connections to the identity chip (ID).