Epson manual MFJ-1278B MULTI-MODE Hardware Jumper Functions, Jumper # Position Function

MFJ-1278B MULTI-MODE HARDWARE

JUMPER FUNCTIONS

The following table lists the function of each jumper on the MFJ-1278B. For normal operation a shorting jumper must be placed on the following connectors: JMP 5; JMP 8; JMP 9 pins 2,3; JMP 13; JMP 14 pins 1,2; JMP 16 pins 1,3 and pins 2,4; JMP 18 pins 1,2; JMP 19 outside pair (one top,one bottom); JMP 22 pins 2,3; JMP 24 pins 1,2; JMP 26 pins 1,2; JMP E, F, G, H. Also on the mode disconnect header J4 the following pins need jumpers pins 1,2 11,12 13,14 17,18.

Table 8-1: Jumper Function

Jumper #	Position	Function
JMP1	Pin 1 & 2	!DCD (RS-232C) stays on
	Pin 2 & 3	!DCD (RS-232C) stays off
	OFF (default)	!DCD reflects connect status
JMP2	Pin 1 & 2 (default)	4.92 MHz CPU clock
	Pin 2 & 3	2.46 MHz CPU clock
JMP4	ON	disable Tx watch-dog
	OFF (default)	enable Tx watch-dog
JMP5	ON (default)	Lithium battery connected
	OFF	Lithium battery disconnected
JMP7	ON	analog loopback mode
	OFF (default)	normal modem operation
JMP8	ON (default)	demodulator enabled
	OFF	demodulator calibrate
JMP9	Pin 1 & 2	calibrate U16 tones
	Pin 2 & 3 (default)	normal modem operation
JMP10	ON	digital loopback mode
	OFF (default)	normal modem operation
JMP11	LEFT	transmit data NRZ
	RIGHT (default)	transmit data NRZI