HARDWARE
TB1 – POWER
- A.C. power connections
1
G
Ground
Earth ground line
2
N
Neutral
Non-fused neutral line
3
H
Hot
Fused line
TB2 – RELAYS
– Set point relay contacts
The relays, which are mechanical, can switch 3A, 250V A/C or D/C loads. The contacts are
“dry;” they do not have any potential.
1 L
2 +
CH1 contact
Channel 1 low-level or high-level relay contact.
3 R
4 +
CH2 contact
Channel 2 low-level or high-level relay contact.
TB3 – ANALOG OUT
– 4-20mA analog outputs
1
+L
CH1 positive signal
2
-L
CH1 negative signal
Channel 1, active 4-20mA analog output.
3
+R
CH2 positive signal
4
-R
CH2 negative signal
Channel 2, active 4-20mA analog output.
TB4 – CH1 (EI2000-LEFT)
Scale input 1
TB5 – CH2 (EI2000-RIGHT)
Scale input 2 (Note: Connections 6 & 7 are not present on TB5)
1 +E Positive
excitation
Positive power supply for the scale base, which is 5V +/-
5%.
2 +S Positive
signal Positive scale signal input
3
-S
Negative signal
Negative scale signal input
4 -E Negative
excitation
Negative power supply voltage (return) for the scale base,
which is 0 volts referenced to signal ground.
5
SH
Shield
Connected to earth ground
6 + Positive
sense
TB4 only: Connected to the negative sense (or negative
excitation if the negative sense terminal is not present) at
the scale summing board to allow the voltage drop of the
cable to be compensated for.
7 - Negative
sense
TB4 only: Connected to the positive sense (or positive
excitation if the positive sense terminal is not present) at the
scale summing board to allow the voltage drop of the cable
to be compensated for.
TB6 – Serial I/O and SWITCH INPUT
1
A
RS485 – A line
2
B
RS485 – B line
Half-duplex RS485 interface.
3 C
Common
This is signal ground for the RS232, RS485 and switch
input, IN.
4
R
RS232 – Rx line
RS232 receive
5
T
RS232 – Tx line
RS232 transmit
6 IN
Switch
input
The external, potential free (dry) switch connects to IN and
C terminals.
