English (GB)
8
5.2 Setting the parity
The parity can be set either manually by using SW3 or via
software-defined settings.
Manual setting of parity
Default byte format (11 bits):
• 1 start bit
• 8 data bits (least significant bit sent first)
• 1 parity bit (even parity)
• 1 stop bit.
The default setting of the CIM 200 Modbus module is even parity
(1 stop bit). It is possible to change the parity using DIP switch
SW3. The parity can be changed to no parity (2 stop bits).
See fig. 9.
Fig. 9 Parity
DIP switch settings
Software-defined parity and stop bits
When SW4 and SW5 are set to "software-defined", the value in
the holding registers at addresses 00009 and 00010 will override
the setting of SW3. See figs 8 and 9.
The software-defined parity and stop bit values will be stored in
the communication interface and will remain after a power-off.
5.3 Modbus address selection
A Modbus slave on a Modbus network must have a unique
address from 1-247. Address 0 is reserved for broadcasting, and
is not a valid slave address.
To set the Modbus address, two hexadecimal rotary switches
(SW6 and SW7) are used. See fig. 10.
Fig. 10 Setting the Modbus address
For a complete overview of Modbus addresses, see section
14. Fault finding.
5.4 Termination resistor
The termination resistor is fitted on the CIM 200 Modbus module
and has a value of 150 Ω.
The CIM 200 has a DIP switch with two switches (SW1 and SW2)
for cutting the termination resistor in and out. Figure 11 shows the
DIP switches in cut-out state.
Fig. 11 Cutting the termination resistor in and out
DIP switch settings
Default setting: Termination resistor cut out.
Cable length
Grundfos recommends the following maximum lengths:
When software-defined transmission speed is
enabled (ON), software-defined parity and stop
bits are also enabled.
TM04 1709 0908
Parity SW3
Even parity, 1 stop bit OFF
No parity, 2 stop bits ON
Software-defined parity
Value to set in
register 00009
No parity [default] 0
Even parity 1
Odd parity 2
Software-defined stop bit
Value to set in
register 00010
1 stop bit [default] 1
2 stop bits 2
Before the parity and stop bits can be set via
software-defined settings, SW4 and SW5 must be
set to ON.
TM04 1706 0908
The Modbus address must be set decimally from
1 to 247.
TM04 1701 0908
Status SW1 SW2
Cut-in ON ON
Cut-out
OFF OFF
ON OFF
OFF ON
Bits/s
Maximum cable length
Terminated cable Unterminated cable
[m/ft] [m/ft]
1200-9600 1200/4000 1200/4000
19200 1200/4000 500/1700
38400 1200/4000 250/800
To ensure a stable and reliable communication, it
is important that only the termination resistor of
the first and last units in the Modbus network are
cut in.
All switch settings will be effective immediately
after setting the values. No power-off needed.
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