6
2 Connecting the Options Unit
To connect the Options Module to the GIMA:
1
Isolate all inputs/outputs to the GIMA.
2
Check the ratings on the options module and meter to ensure compatibility.
3
Use a sharp knife to remove the cutout section from the rear of the GIMA.
Ensure the knife blade does not penetrate more than 3mm.
4
Insert the Options Module into the slot on the rear of the meter.
5
Slide the Module fully home until all four mounting lugs cluck into place, as
shown below.
Figure 2.1. Options Module attached to GIMA
27
Meter Response
The reply confirms the data address and amount of data received.
4.5.12 Exception Responses
When a host sends a query to an individual meter on the network, it expects a
normal response. In fact, one of four possible events may occur as a result of the
query:
If the Options Unit receives the message with no communication errors, and
can handle the query, it will reply with a normal response.
If the Options Unit does not receive the message due to a communication
failure, no response will be returned and the host will eventually time-out.
If the Options Unit receives the message but detects a communication error
via its CRC, no response will be returned and the host will time-out.
If the Options Unit receives the query with no communication errors, but can-
not handle the query (out of range data or address), the response will be an
Exception Response informing the host of the nature of the error.
An Exception Response differs from a normal response in its Function Code and
Data Fields.
E
T
Y
B
E
L
P
M
A
X
E
S
S
E
R
D
D
A
R
E
T
E
M
1
H
9
1
N
O
I
T
C
N
U
F
2
H
0
1
)
e
t
y
B
h
g
i
H
s
s
e
r
d
d
A
(
R
E
B
M
U
N
E
L
B
A
T
3
H
D
0
)
e
t
y
B
w
o
L
s
s
e
r
d
d
A
(
T
E
S
F
F
O
E
L
B
A
T
4
H
3
0
)
e
t
y
B
h
g
i
H
(
)
N
(
S
D
R
O
W
A
T
A
D
F
O
R
E
B
M
U
N
5
H
0
0
)
e
t
y
B
w
o
L
(
)
N
(
S
D
R
O
W
A
T
A
D
F
O
R
E
B
M
U
N
6
H
3
0
)
e
t
y
B
h
g
i
H
(
M
U
S
K
C
E
H
C
7
H
1
7
)
e
t
y
B
w
o
L
(
M
U
S
K
C
E
H
C
8
H
C
7