VICI

AG INTERNATIONAL
North America, South America, and Australia/Oceania: Europe, Asia and Africa:
P.O. Box 55603, Houston, TX 77255 • USA Parkstrasse 2, CH-6214 Schenkon • Switzerland
Phone: +1 713-688-9345 | valco@vici.com Phone: +41 41 925 6200 | info@vici.ch

CHEMINERT MODEL C55 & C65(Z) SELECTORS

®

INSTALLATION & MAINTENANCE

Technical Note 821

The Cheminert® C55 (HPLC) and C65 (LC) series selectors are integrated motor/valve assemblies designed
specifically to be built into OEM systems.

INITIAL PRECAUTIONS
After unpacking the injector, leave the protective cap over the valve ports until you are ready to install
the unit. As supplied, all surfaces are clean and free of contaminants, and must be kept clean to prevent
valve damage. Open ports and fittings cause unnecessary risk of particulate matter entering the valve and
scratching the sealing surfaces, which is the most frequent cause of premature valve failure.

WARNING: The most common source of particulate and chemical contamination is

tubing which has not been properly cleaned before installation in the valve. Failure
to observe proper cleanliness procedures during installation of the valve voids the
manufacturer’s warranty.

INSTALLATION
MOUNTING
Mount the unit in a horizontal position. Avoid any orientation that positions the control board on the bottom,
where it could be damaged by leakage. Mounting hole locations are shown in Figure 1. There are four 4-40
tapped mounting holes on the valve face of the gearbox and another four on the side of the gear housing.

NOTE: 8 and 10 port valves with 1/4-28 fittings have larger bodies which block the mounting holes on the
valve face, as highlighted in the red box of Figure 1.

ELECTRICAL CONNECTIONS
Cables for electrical connections can either be ordered from VICI or constructed in-house. To order from VICI,
request product numbers I-25176 for the I/O control cable and I-24780 for the power cable.
If you prefer to make your own cables for I/O control and power:
1. Use a Molex 26-03-4020 shell and 08-58-0111 contacts with 22 awg stranded wire to supply 24 volt current
(3 amps recommended) to the connector marked J1 (See Figure 3). The motor can draw as much as 2.5
amps during movement so make sure there is adequate power available, and do not share power with other
sensitive circuits.

VICI Technical Note 821 - Revised 06/2020 1

 FIGURE 1: Dimensions for models with single stage gearbox (top) and dual stage gearbox (bottom).
The shading indicates the area to check for a quick model identification.

VALVE SCHEMATICS & SWITCHING TIMES

FIGURE 2: Valve schematics Table 1: Time required to move between positions

SINGLE STAGE
1 POSITION EACH ADDTL. POSITION
4 positions 150 ms 111 ms
6 positions 115 ms 71 ms
8 positions 96 ms 55 ms
10 positions 85 ms 43 ms

DUAL STAGE
1 POSITION EACH ADDTL. POSITION
6 positions 269 ms 230 ms
8 positions 212 ms 173 ms
10 positions 184 ms 133 ms
12 positions 154 ms 118 ms

VICI Technical Note 821 - Revised 06/2020 2

 NOTE: On the initial power up, the actuator automatically executes a startup sequence to find its location
flag. This sequence, which takes 1.45 seconds on a single stage actuator and 4.2 seconds on a dual stage
actuator, ends with the valve in position 1. After the sequence is finished, the valve can be positioned as
desired.

2. Use an Amphenol 65846-015LF shell and 47715- FIGURE 3: Power connector J1, pin view.
000LF contacts to make the connection to Connector J3,
which provides the contact closure input and detects the
output of the position sensor (see Figure 4 and Table 2).
Position feedback is obtained from the A and outputs
shown in Figure 4. These are 5 volt tolerant, 3 volt
logic outputs, sourcing and sinking a maximum of 20
milliamperes each. An output will go high (+3V) when the
valve reaches the respective position. FIGURE 4: Control connector J3, pin view.

CAUTION: Do not attempt to source or sink

more than 20 mA from either output.

MOTOR CONTROL METHODS

STEP CONTACT CLOSURE
Applying a connection between the common and “A
contact” pins causes the selector to move to the next TABLE 2: Connector J3 pin assignments
position in the direction set Table 2: Connector J3 by (Colors are in reference to VICI cable I-25176)
Jumper 1. (See “Jumper Settings” on page 3) The
connection pin assignments must be opened before PIN # COLOR FUNCTION
another step can be made.
1 Green A output (3.3 VDC)

HOME CONTACT CLOSURE 2 Unused

Applying a connection between the common and “B 3 White B output (3.3 VDC)
contact” pins causes the selector to move to the HOME
position (position 1) in the direction set by Jumper 1. 4 Black A contact
(See “Jumper Settings” on page 3) The connection must 5 Shield Common
be opened before another step can be made.
6 Red B contact

JUMPER SETTINGS FIGURE 5: Location of jumpers

Factory-set jumpers determine the actuator motor’s angle of rotation
(a function of the number of ports in the valve head) and direction of
rotation; the default direction is clockwise (i.e., stepping from position 1
to position 2), as viewed from the motor end of the assembly.
Figure 5 shows the jumper locations, with a jumper installed in jumpers
position 1. Jumper 4 is always installed for mult-iposition (selector
applications. (For two position applications, refer to Technical Note
819.)
Configuration information is presented verbally below. For a graphic
presentation of the decision process, refer to Figure 6.

VICI Technical Note 821 - Revised 06/2020 3

 SETTING THE ROTATION DIRECTION TABLE 3: Jumper settings for rotation direction
(as viewed from the motor end)
1. Interrupt power to the motor by detaching
power connector J1. DIRECTION JUMPER 1
2. Remove/install jumper 1 as required. (Refer to Clockwise No
Table 3)
Counter-clockwise Yes
3. Re-attach connector J1. The change takes effect
when the motor is powered up.

SETTING THE ANGLE OF ROTATION TABLE 4: Jumper settings for number of ports

SINGLE STAGE DUAL STAGE

If you are changing the valve head to one with a
different number of ports, jumpers 2 and 3 must JUMPER: 2 3 JUMPER: 2 3
be reconfigured. Remember that jumper 4 must 4 post. Yes Yes 6 post. Yes Yes
remain empty for two position applications.
6 post. No No 8 post. No No
To set the motor for the proper amount of rotation:
8 post. Yes No 10 post. Yes No
1. Interrupt power to the motor by detaching
power connector J1. 10 post. No Yes 12 post. No Yes
2. Refer to Figure 1 to determine if the unit has a
single stage gearbox or a dual stage gearbox.
3. Consult Table 4 to determine the correct jumper arrangement, and install jumpers as indicated. (For the
purpose of determining rotation, the number of ports referenced means the number of ports forming a
circle around the center port; the center port itself is not counted.)
4. Re-attach connector J1. The change takes effect when the motor is powered up.

RESTORING THE DEFAULT BAUD RATE FIGURE 6: Jumper position to

To restore the baud rate to the factory default of 9600: restore default baud rate

1. Interrupt power to the motor by detaching power connector J1.

2. Remove jumpers 3 and 4, noting their location for proper
re-installation.
3. Install a jumper as shown in Figure 6.
4. Re-attach connector J1. The rate change takes effect when the
motor is powered up.
5. Detach power connector J1 and restore jumpers 3 and 4 to their previous configuration.
6. Re-attach connector J1.

VICI Technical Note 821 - Revised 06/2020 4

 FIGURE 7: Decision tree for setting jumpers.
NOTE: The gearbox type is sensed automatically.
For a visual determination, refer to Figure 1.

VICI Technical Note 821 - Revised 06/2020 5

 ACTUATORS WITH OPTIONAL SERIAL CONTROL TABLE 5: Pin assignments
(MUST BE SPECIFIED AT TIME OF PURCHASE)
PIN # RS-232 RS-485
RS-232 and RS-485 communication require a
terminal emulation program. There are many 1 Ground Ground
emulators available for free on the internet. Though
the programs vary, in general you will select “Serial” 2 Transmit to host A (–)
from among various types of connections, select the 3 Receive from host B (+)
COM port which will be used, name the connection,
and set the port baud rate as shown in Table 7 Requires: Amphenol shell 102241
(9600, or 9K60, is the factory default). The rest of the Amphenol pins 187756-1
configurations are fixed at no parity, 8 data bits, 1 OR VICI cable I-22697
stop bit, no hardware or software handshaking.
A three-pin connector is used for the serial interface: CONTROL COMMAND LIST
pin assignments are listed in the table at right. Use GO[nn] Move to nn position
VICI cable I-22697 or make your own with the parts CW[nn] Move Clockwise to nn Position
named below the table. The implementation of RS-
CC[nn] Move Counter Clockwise to nn Position
485 is half-duplex two wire with ground, and uses
the same 3 pin output connector as RS-232. CP Returns Current Position
With the software running, check the communication SB[nnnnn] Set the Baud Rate to nnnnn
link between the computer and the serial port by VR Firmware Version
typing /?<enter>. If the link is functioning, the menu
/? Displays This List
to the right will appear on your monitor:

SERIAL COMMUNICATION PROTOCOL

Serial communication is based on an ASCII string protocol. Carriage Return (OD hex) characters parse the
communications by defining the end of each command. Software flow control (Xon/Xoff) and hardware
handshaking are not supported. The table below (Table 6) describes and explains all the commands available.
A fuller explanation follows.

VICI Technical Note 821 - Revised 06/2020 6

 TABLE 6: Commands and descriptions

SERIAL COMMANDS

CCn Sends the actuator counterclockwise to position n, where n is A or B

CP Displays the current position
CWn Sends the actuator clockwise to position n, where n is A or B
DTn Displays/set an inject delay interval (n seconds before the actuator returns to previous position)
E+/E- Enable/disable the terminal echo and prompt (not available for RS-485)
GOn Sends the actuator to position n, where n is A or B
IC+/IC- Enable/disable the invalid command response
LF+/LF- Add/remove line feed to serial string, output only (not available for RS-485)
MD Displays the unit model number
QS+/QS- Enable/disable quiet serial output during startup (not available for RS-485)
R+/R- Enable/disable position reporting
RC Report the valve configuration
SB Displays the current baud rate
SBnnnn Sets the baud rate. Refer to the table below for nnnn values.
SN Displays the unit serial number
TO Sends the actuator to the opposite position (ignored in single contact closure mode)
TT Sends the actuator to the opposite position, delays, and returns to original position (ignored in
dual contact closure mode)
VR Displays the part number and date of the firmware
/? Displays a list of valid commands

VICI Technical Note 821 - Revised 06/2020 7

 COMMAND REFERENCE
NOTE: Repeated direction reversals (CC and CW commands) without passing the internal orientation
flag located between the two topmost ports (for example, ports 5 and 6 of a 6 position model) are not
recommended, due to possible rotor slippage.
TABLE 7: Baud rate values
CC [nn] Moves the actuator in a counterclockwise direction, where
BAUD RATE nnnn
nn = a number from 1 to the current set number of positions
(set by jumper—see page 3) 4800 4K80
Examples 9600 9K60
Command: CC<enter>
19200 19K2
Sends the actuator counterclockwise one position
Command: CC3<enter> 38400 38K4
Sends the actuator counterclockwise to position 3
57600 57K6
CP Displays the current position of the actuator
115200 115K
Example
Command: CP<enter>
Returns (via the serial port) the current position, either A or B
CW [nn] Moves the actuator in a clockwise direction, where
nn = a number from 1 to the current set number of positions (set by jumper—see page 3)
Examples
Command: CW<enter>
Sends the actuator clockwise one position CW3<enter>
Command: CW3<enter>
Sends the actuator clockwise to position 3

SB [nnnn] Sets the baud rate, where

nnnn = a value from the table at right
Example
Command: SB19K2<enter>
Sets the baud rate to 19200
GO [nn] Moves the actuator to position nn via the shortest path, where
nn = a number from 1 to the current set number of positions (set by jumper—see page 3)
Examples
Command: GO<enter>
Advances the actuator to the next position
Command: GO3<enter>
Moves the actuator to position 3 via the shortest path
VR Reports the current firmware version of the main PCB (via the serial port)
Example
Command: VR<enter>
Returns (via the serial port) the current revision of the firmware

VICI Technical Note 821 - Revised 06/2020 8

 FIGURE 8: Serial boards

ADDITIONAL INFORMATION ON THE RS-485 OPTION

HARDWARE PROTOCOL
The RS-485 hardware protocol is half-duplex implementation – two wires with a ground. There are two
connectors, J1 and J2, which are connected in parallel to allow easy daisy chaining of multiple devices.

HARDWARE TERMINATION
The RS-485 port on the host computer or controlling device generally includes terminating resistors, so on
short cables no termination is required. However, if many devices are attached and/or the actuator is on the
end of a long communication cable, the termination jumpers on the furthest device from the master RS-
485 controller should have termination enabled. To use termination resistors, install a jumper on the header
labeled HDR1, oriented as shown in Figure 8 on page 6.

HARDWARE ID SET
The firmware requires a serially-addressed ID, which on this board is set by the 16 position rotary switch
labeled SW1. The ID is set either as a number from 0 - 9 or a letter from A - F, as selected by the arrow on the
face of SW1.

SOFTWARE PROTOCOL
The software protocol requires a forward slash [/] as a beginning-of-message character, followed by a single
character ID. The end-of-message character which terminates the command is a <CR>. The standard RS-232
serial port commands are then supported within that protocol.
Example:
With the settings in Figure 8, the RS-232 command VR<enter> becomes /0VR<enter> in the RS-485
protocol; / is the start-of-message character, 0 is the current ID of the device, and VR<enter> is the
command to be executed.
NOTE: Of the commands on listed on page 7, E+/E-, LF+/LF-, and QS+/QS- work only for RS-232; they are
not available in RS-485 operation.

VICI Technical Note 821 - Revised 06/2020 9

 CLEANING AND ROTOR REPLACEMENT FIGURE 9: Exploded view of a typical
injector
These valves have polished sealing surfaces which must
be protected during any disassembly or cleaning procedure.
Work in a clean environment and always set parts on a
soft tissue or clean paper. Cleaning a valve can often be
accomplished by flushing all the lines with appropriate
solvents. Do not disassemble the valve unless
system malfunction is definitely isolated to the valve.

DISASSEMBLY (REFER TO FIGURE 9)

1. Use a 3/32” hex driver to remove the 5-40 socket head
screws that secure the stator to the valve body. Alternate
among the five screws in the sequence indicated in FIGURE 10: Loosening and
Figure 10, loosening them in quarter-turn (90°) increments tightening order
until all load is removed.
2. To ensure that the sealing surface of the stator is not
damaged, rest it on its outer face. Or, if the tubing is
still connected, leave it suspended by the tubing.
3. With your fingers or a small tool, gently pry the rotor
away from the driver.
4. Examine the rotor sealing surface for scratches. If you see
any, the rotor should be replaced.
5. Examine the stator sealing surfaces. If scratches are visible between the ports, that part should be
replaced or resurfaced. Call VICI for help in determining if resurfacing is feasible.
6. Clean all the parts thoroughly with an appropriate solvent, taking care that no surfaces get scratched. (A
common problem with HPLC is the formation of buffer crystals, which are usually water-soluble.) It is not
necessary to dry the rotor.

REASSEMBLY
1. Replace the rotor in the driver, making sure that the rotor sealing surface with its engraved flow passages
is facing out. The tabs on the rotor have an asymmetrical pattern to prevent assembly with improper
orientation.
2. Replace the stator. Insert the five socket head screws and tighten them gently until they start to get snug.
Alternate among the five screws in the sequence indicated in Figure 10, tightening them in quarter-turn
(90°) increments until the stator is flush against the valve body. Do not over-tighten the screws – they
simply hold the assembly together and do not affect the sealing force, which is automatically set as the
screws pull the stator against the valve body.
3. Test the valve by pressurizing the system. If it doesn’t hold pressure, the valve should be returned to VICI
Valco for repair.

VICI Technical Note 821 - Revised 06/2020 10