Emerson Static Transfer Switch 15.2.9 RS-232 Port, Terminal Port Connections, MTA plug pinout

Specifications

15.2.9RS-232 Port

The unit is equipped with an RS-232 port for connecting a terminal or PC. See Figure 28 for the port’s location.

See 12.1 - Using the RS-232 Port for instructions on using a PC terminal with the unit.

15.2.10Terminal Port Connections

The system has an asynchronous serial port configured as Data Terminal Equipment for terminal access only (half duplex). The CPU services the terminal port with no handshaking. The serial port conforms to RS-232 levels with a data format of 9600 Baud, 1 start bit, 8 data bits, and no parity bits. The serial port is 1000VDC isolated (non-SELV) and ESD protected to 15kV air discharge. The con- nector is a 6 Pin MTA plug with connections shown below.

Table 21 MTA plug pinout

Pin	Signal Name	Function / Comments
1	ISO_GND	Isolated service terminal ground
2	ISO_TXD	Isolated service terminal transmit output
3	ISO_RXD	Isolated service terminal receive input
4	NC	No Connection
5	NC	No Connection
6	NC	No Connection

A DB9 male connector is added and connected parallel to the 6 position header. It is configured as DTE.

Table 22	DB9 pinout
Pin		Signal Name	Function / Comments
1		NC	No Connection
2		ISO_RXD	Isolated service terminal transmit output
3		ISO_TXD	Isolated service terminal receive input
4		NC	No Connection
5		ISO_GND	Isolated service terminal ground
6		NC	No Connection
7		NC	No Connection
8		NC	No Connection
9		NC	No Connection

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