Termination Resistor; Setting The Parity - Grundfos CIM 2 Series Installation And Operating Instructions Manual

3.3 Termination resistor

The termination resistor is fitted on the CIM 2XX
Modbus module and has a value of 150 Ω.
The CIM 2XX has a DIP switch with two switches
(SW1 and SW2) for cutting the termination resistor in
and out. Figure 5 shows the DIP switches in cut-out
state.
SW1 SW2
Fig. 5 Cutting the termination resistor in and
out
DIP switch settings
Status
Cut-in
Cut-out
Cable length
Maximum cable length
Terminated
bits/s
cable
[m/ft]
1200-9600 1200/4000
19200 1200/4000
38400 1200/4000
To ensure a stable and reliable
communication, it is important that
Note
only the termination resistor of the first
and last unit in the Modbus network is
cut in. See fig. 2.
10
SW1 SW2
ON ON
OFF OFF
ON OFF
OFF ON
Unterminated
cable
[m/ft]
1200/4000
500/1700
250/800

3.4 Setting the parity

The parity can be set either manually by using SW3
or via software-defined settings.
Manual setting of parity and stop bit
Default byte format (11 bits):
• 1 start bit
• 8 data bits (least significant bit sent first)
• 1 parity bit (even parity)
• 1 stop bit.
See fig. 6.
SW3
Fig. 6 Parity
DIP switch settings
Parity
Even parity, 1 stop bit [default]
No parity, 2 stop bits
Software-defined parity and stop bit
When SW4 and SW5 are set to "software-defined",
the value in holding registers at addresses 00009
and 00010 will override the setting of SW3. See figs
6 and 7.
Software-defined parity
No parity [default]
Even parity
Odd parity
Software-defined stop bit
1 stop bit [default]
2 stop bits
Before the parity and stop bit can be set
Note
via software-defined settings, SW4 and
SW5 must be set to ON.
SW3
OFF
ON
Set register value
00009
0
1
2
Set register value
00010
1
2