Gamma Vacuum Digitel MPC 635941 User manual

Digitel MPC Technician's Manual
Part Number: 500000, Revision: J
Gamma Vacuum, LLC
Copyright © 2003
Gamma Vacuum, LLC
12912 Ventura Court No. 28
Shakopee, MN 55379
USA

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I. Contents
I. Introduction......................................................................................................................................... 6
Description.............................................................................................................................................. 6
MPC Configurations........................................................................................................................... 6
RS-232/422/485 Serial Interface......................................................................................................... 6
Set Points ............................................................................................................................................ 6
High Voltage Modules........................................................................................................................ 7
Analog Outputs................................................................................................................................... 7
SAFE-CONN™ High-Voltage interlock............................................................................................ 7
AUTORUN™..................................................................................................................................... 7
Remote TSP/NEG Control Option...................................................................................................... 7
High-Voltage/TSP Filament Interlock Option.................................................................................... 8
Specifications.......................................................................................................................................... 9
II. Installation......................................................................................................................................... 10
Inspection for Damage.......................................................................................................................... 10
Installing the DIGITEL MPC ............................................................................................................... 10
Required items.................................................................................................................................. 10
Procedure .......................................................................................................................................... 11
Installing the Remote TSP/NEG Control Option.................................................................................. 11
Required Items.................................................................................................................................. 12
Procedure .......................................................................................................................................... 12
SAFE-CONN™ Installation on an Ion Pump....................................................................................... 13
Required Items.................................................................................................................................. 13
Procedure .......................................................................................................................................... 13
III. Operation....................................................................................................................................... 15
Front Panel Description ........................................................................................................................ 15
Rear Panel Description ......................................................................................................................... 17
Operating the Ion Pump........................................................................................................................ 18
To Evacuate the Pump...................................................................................................................... 18
To Start the Pump ............................................................................................................................. 18
Using the Controls ................................................................................................................................ 19
Display Selection.............................................................................................................................. 19
Disable and Enable ........................................................................................................................... 19
Keypad.............................................................................................................................................. 19
Program Mode Keys......................................................................................................................... 21
Menu Key.......................................................................................................................................... 29
Display Messages.................................................................................................................................. 41
Event Log.............................................................................................................................................. 41
General Description.......................................................................................................................... 41
Front Panel Display of Events .......................................................................................................... 42
Serial Port Output of Events............................................................................................................. 42
Analog Outputs..................................................................................................................................... 43
Voltage measuring............................................................................................................................ 43
Current measuring............................................................................................................................. 43
High Voltage/TSP Filament Interlock Option...................................................................................... 44
Serial Interface...................................................................................................................................... 44
Standard ............................................................................................................................................ 44
Specifics............................................................................................................................................ 45
IV. Service........................................................................................................................................... 52

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MPC Components................................................................................................................................. 54
Maintenance Procedures....................................................................................................................... 54
Removing the Top Cover.................................................................................................................. 55
Cleaning the Chassis......................................................................................................................... 55
Cleaning the Fan Filter...................................................................................................................... 55
Replacing Fuses................................................................................................................................ 55
Input and Output Voltage Selection...................................................................................................... 56
Input Voltage Selection Procedure ................................................................................................... 56
Output Voltage Selection Procedure................................................................................................. 57
Voltage Polarity Configuration......................................................................................................... 57
PROM Change Procedure..................................................................................................................... 58
Rear Panel Connector Pinouts .............................................................................................................. 60
Connector J104 — Set Point and Analog Output Signals ................................................................ 60
Connector J505 — Remote TSP/NEG Control Signals.................................................................... 61
Connector J112 — Serial Interface Signals...................................................................................... 61
Serial Communication Protocol Selection............................................................................................ 62
Remote TSP/NEG Control Option........................................................................................................ 64
Removing the Panels of the Remote TSP/NEG Control .................................................................. 64
Input Voltage Selection of the Remote TSP/NEG Control .............................................................. 65
Connecting a High Current Cable to the Remote TSP/NEG Control............................................... 65
Accessory Equipment ........................................................................................................................... 66
V. Appendix A....................................................................................................................................... 67
Menu Flowcharts .................................................................................................................................. 67

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II. Figures
Figure I-1. Photograph of the Digitel MPC............................................................................................... 6
Figure I-2. Remote TSP/NEG Control Option. ......................................................................................... 8
Figure II-1. MPC Rear Panel HV and SAFECONN Connectors. ........................................................... 11
Figure II-2. Remote TSP/NEG Control Connections.............................................................................. 12
Figure II-3. Diagram of Remote TSP/NEG Control................................................................................ 12
Figure II-4. High Current Cable............................................................................................................... 13
Figure II-5. SAFECONN Installation Diagram #1.................................................................................. 13
Figure II-6. SAFECONN Installation Diagram #2.................................................................................. 14
Figure III-1. Front Panel Controls and Indicators.................................................................................... 15
Figure III-2. Rear Panel Connectors........................................................................................................ 17
Figure III-3. DISPLAY SELECT key ..................................................................................................... 19
Figure III-4. Keypad. ............................................................................................................................... 20
Figure III-5. Menu key............................................................................................................................. 20
Figure III-6. Program Mode Select keys.................................................................................................. 21
Figure III-7. Setting pump size................................................................................................................. 31
Figure III-8. Reaching PREFRENCES Submenu.................................................................................... 31
Figure III-9. Reaching the Configuration Submenu................................................................................ 33
Figure III-10. Reaching the DIAGNOSTCS Submenu........................................................................... 38
Figure III-11. Line drawing of the optional interlock connector J506. ................................................... 44
Figure IV-1. Location of MPC Components. .......................................................................................... 54
Figure IV-2. Location of Fuses on the AC Power Board. ....................................................................... 55
Figure IV-3. Input and Output Voltage Conversion — Location of Components. ................................. 56
Figure IV-4. Voltage Polarity — Location of Components. ................................................................... 58
Figure IV-5. CPU Board — Location of PROM..................................................................................... 59
Figure IV-6. Rear Panel Connectors........................................................................................................ 60
Figure IV-7. Selecting the Serial Interface Protocol................................................................................ 62
Figure IV-8. Remote TSP/NEG Control — Location of Components.................................................... 64

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III. Tables
Table I-1. Specifications DIGITEL MPC.................................................................................................. 9
Table II-1. High Voltage and SAFE-CONN Connectors. ....................................................................... 11
Table III-1. Front Panel Controls and Indicators..................................................................................... 16
Table III-2. Program Mode Select Keys.................................................................................................. 21
Table III-3. Menu Hierarchical System................................................................................................... 30
Table III-4. Error Codes........................................................................................................................... 39
Table III-5. Display Messages................................................................................................................. 41
Table III-6. The Five Parts of the Event Record...................................................................................... 42
Table III-7. Serial Command Packet Description.................................................................................... 46
Table III-8. Serial Response Packet Description..................................................................................... 48
Table III-9. RS-232/422/485 Commands — PHI Standard Serial Interface........................................... 49
Table III-10. CRC Checksum Calculation............................................................................................... 51
Table IV-1. MPC Component Parts List.................................................................................................. 54
Table IV-2. Routine Maintenance Schedule............................................................................................ 55
Table IV-3. Part Numbers (p/n) — Fuses on the AC Power Board. ....................................................... 56
Table IV-4. Input Voltage Conversion Fuse Values for the DIGITEL MPC.......................................... 57
Table IV-5. Input Voltage Conversion Connectors for the DIGITEL MPC. .......................................... 57
Table IV-6. Connector J104 Pinouts........................................................................................................ 60
Table IV-7. Connector J505 Pinouts........................................................................................................ 61
Table IV-8. Connector J112 Pinouts........................................................................................................ 61
Table IV-9. Serial Interface DIP Switch Setting. .................................................................................... 63
Table IV-10. Optional Accessory Equipment.......................................................................................... 66
Table V-1. Drawings and Parts Lists....................................................................................................... 67
Table V-2. Schematics............................................................................................................................. 67

I. Introduction
The manual is divided into five sections. Section 1 contains a brief description and
specifications of the DIGITEL™ Multiple Pump Control (MPC). Sections 2 (page 10) and 3
(page 15) explain the installation and operation procedures, respectively. Section 4 (page 52)
provides information for servicing the unit.
Description
The DIGITEL™ MPC is a pump power supply and system control. It is designed to operate up
to two ion pumps and a titanium sublimation pump (TSP) or non-evaporable getter (NEG) pump,
all independently and simultaneously. The MPC can accommodate pump sizes from 10 l/s and
up to 1200 l/s. It operates on 115 or 230 VAC, 50 or 60 Hz.
The MPC (Figure I-1) is a programmable, microprocessor-based unit. It contains a metering
circuit, 8 process setpoints, communications interface RS-232/422/485, and up to two
independent high voltage modules. The front panel display provides direct readout of the ion
pump voltage, current, or pressure. Ranging is automatic within the selected display mode.
Figure I-1. Photograph of the Digitel MPC.
MPC Configurations
The DIGITEL MPC comes in the following configurations:
•635941 base unit plus one medium HV module (200W, 100mA)
•635942 base unit plus one large HV module (1000W, 500mA)
•635943 base unit plus two medium HV modules
•635944 base unit plus two large HV modules
•635945 base unit plus one medium and one large HV module
RS-232/422/485 Serial Interface
The DIGITEL MPC can be interfaced and remotely controlled by a computer. All commands
entered from the keypad can be performed from the computer.
Set Points
Eight programmable setpoints, four relay and four TTL (transistor-transistor logic), can be
configured to either supply. Hysteresis and control values can be programmed through the
computer interface or keypad. Nonvolatile memory is used to store setpoint data for up to 10
years without power applied to the unit. Bakeout control is designed into the software and
setpoints.
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High Voltage Modules
The DIGITEL MPC is available with two high-voltage (HV) modules:
•The medium HV module has a starting capacity of 200W, 100 mA. It is intended
to fully operate pumps from 10 l/s to 200 l/s and can be used on larger pumps if they are well
roughed or if under high vacuum.
•The large HV module has a starting capacity of 1000W, 500 mA. It is intended
for pumps from 160 l/s to 1200 l/s.
HV modules are based on transformer design with low noise, high reliability, and overload
protection. Each HV module has a standard output of 7000 VDC. The output voltage can be
configured to ±7000 or ±5600 VDC for operating different pumps or systems. The modules
come with one standard SHV-10 HV connection. For economical operation of more than one
pump, an optional 2nd high-voltage output can be added.
Analog Outputs
Four buffered analog outputs are provided independently from each HV module to connect the
controller to data-acquisition devices. Two of these outputs provide a 0 to 10 volt signal with a
scale factor of 1 volt per 1000V output voltage (VMON). The other 2 outputs are programmable.
SAFE-CONN™ High-Voltage interlock
When operated with SAFE-CONN safety interlocked pumps and cables, the will DIGITEL MPC
automatically shut off high voltage when the high voltage cable is disconnected at either the
pump or controller end. This provides additional protection from possible shock hazard.
AUTORUN™
AUTORUN determines optimum starting and operating conditions based the pump size entered
and then starts and monitors the pump down without assistance. In start mode, because an ion
pump can draw high currents, the DIGITEL MPC goes through a protected-start process,
monitoring current, voltage, power, and time. If the pump starts properly, the MPC
automatically goes into run protection mode. If the pump does not start properly — the
DIGITEL MPC goes into a cool-down mode. If the pump does not start properly after three
tries, it displays PUMP ERROR. The specific error code that identifies the cause of an error can
be found in the Menu mode.
The DIGITEL MPC continuously protects the ion pump during start-up and normal operation.
Ion pump parameters are monitored continuously by the microprocessor. If there is a vacuum
failure, the MPC shuts down high voltage preventing serious damage. It can also detect power
failures and be configured to automatically restart high voltage after a power loss, if desired.
Remote TSP/NEG Control Option
The remote TSP/NEG option allows you to control a TSP (titanium sublimation pump) or NEG
(non-evaporable getter). All commands to operate the Remote TSP/NEG Control can be entered
using the DIGITEL MPC keypad or a host computer. It can operate in current or power control
mode and can be cycled based on time and pressure. In TSP operation the ranges are 0 to 999
seconds for on time and 0 to 999 minutes for off time.
The option consists of:
•Remote TSP/NEG Control unit
•harness inside the DIGITEL MPC

•control cable from the DIGITEL MPC to the Remote TSP/NEG Control
•high-current cable from the Remote TSP/NEG Control to the TSP/NEG
•an AC input power cable
Figure I-2. Remote TSP/NEG Control Option.
High-Voltage/TSP Filament Interlock Option
The remote interlock allows disabling of either the high voltage outputs or TSP filament firing.
The interlock is installed at J506 (on the back panel of the MPC) if the option is installed. A
loopback plug is shipped with the option along with a connector kit for custom configuration by
the user.
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Specifications
Table I-1. Specifications DIGITEL MPC.
Parameter Specification
Operating temperature 0 to 40°C.
Operating humidity 0 to 80% RH (non-condensing).
Storage temperature -20 to 70°C.
Dimensions:
DIGITEL MPC
Remote TSP/NEG
WxHxD: 483 mm (19") x 133mm (5.25") x 476 mm (18.75").
WxHxD: 138 mm (5.4") x 292 mm (11.5") x 219 mm (8.6").
Input power 115 VAC, 230 VAC, or 208 VAC selectable.
Serial interface:
Baud Rate
number of start bits
number of stop bits
parity
number of data bits
9600
one.
one.
none.
eight.
Set points (8):
Type Set points 1 - 4 are relay; Set points 5 - 8 are TTL.
Electrical characteristics Relay: 500 mA, 28V each, maximum.
TTL: 15 mA each, maximum.
response time All MCP parameters are measured at least every 320 milliseconds.
Assuming a set point decision is handled right after measurement is
made, response time is 320 milliseconds. Assuming a set point decision
is made on the next time through the standard loop response time is 640
milliseconds. Relays take a few milliseconds to operate, so this increases
response time slightly.
Line frequency 48 to 62 Hz. No adjustment necessary.
High voltage output:
short circuit
+7000 VDC output standard; ±5600 and -7000 VDC selectable.
Medium HV module: 200W, 100 mA.
Large HV module: 1000W, 500 mA.
Polarity Positive or negative (selectable).
Analog outputs: 0 to 10V
Voltage
Current (outputs are jumper
selectable)
Operating Load
1V = 1000V.
1V = 100mA or 100µA on 500mA HV modules;
1V = 20mA or 20µA on 100mA HV modules
Lowest resistance = 2kΩ.
Pump size Selectable from the keypad (Menu key).
Filament power ramp-up 5 amps per second.

II. Installation
This section details the installation requirements for the DIGITEL™ Multiple Pump Control
(MPC).
WARNING: Gamma Vacuum, LLCs’ products are designed and manufactured to provide
protection against electrical and mechanical hazards for the operator and the area
surrounding the product. The procedures provided in Sections 2 and 5 of this manual and in
other Gamma Vacuum, LLC product manuals must be followed to ensure that these
protections are not impaired in any way.
WARNING: Installation procedures are for use by qualified and authorized personnel who
have experience working with voltages greater than 50 volts. To avoid personal injury, do not
perform any installation or service procedures unless qualified to do so.
Voltages up to 7000V are present. An interlock is provided to shut off power when the top
cover is removed. Do not defeat this interlock.
Do not disconnect the high-voltage cable with power on. After turning power off, allow at
least one minute before disconnecting electrical equipment
Do not operate the control without a proper electrical ground or near water. The control may
be damaged and its safety reduced, if it is operated outside of its specifications.
Inspection for Damage
NOTE: It is the customer’s responsibility to inspect and report any obvious shipping damage to
the carrier, typically within 30 days. Before installing Gamma Vacuum, LLC equipment, inspect
it for damage that may have occurred during shipment.
Installing the DIGITEL MPC
The DIGITEL MPC can be mounted in a standard 19 in. (48.3 cm) rack or used as a free-
standing unit. Make sure to provide clearance for air flow into top cover vent holes and out rear
mounted fan. Installation should be in such a manner as to make the rear power cord accessible.
NOTE:This unit can radiate radio frequency energy. Be sure that you install it according to
instructions or interference could result.
The unit protects against interference in a commercial environment. If operation in a residential
area causes interference, it is the user’s responsibility to correct this problem.
Required items
You need the following items to install the MPC:
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1. 3-wire, detachable AC input power cable (included with DIGITEL)
2. high voltage (HV) cable for each pump (ordered separately)
3. safety ground cable for each pump (ordered separately)
Procedure
Perform the following procedure to install the MPC:
1. Place the unit in its location and secure as necessary.
2. Connect the safety ground cable between the pump and safety ground stud at the
DIGITEL rear panel (Figure II-1).
3. Connect the high voltage cable to the ion pump and to the appropriate high voltage
jack on the DIGITEL rear panel. See Figure II-1 and Table II-1.
4. If you have the optional SAFE-CONN feature, an additional connector is part of the
HV connector. Connect it to the appropriate SAFE CONN jack. See Figure II-1 and
Table II-1.
5. Verify correct input voltage requirements. Connect the AC input power cable to
input power receptacle on the DIGITEL rear panel.
6. Switch on the DIGITEL and set correct pump size.
HV connect - supply 1
safety ground cable
SafeConn connect - supply 1
Optional
SafeConn connect - supply 1
Optional
HV connect - supply 1
ac
input
Figure II-1. MPC Rear Panel HV and SAFECONN Connectors.
Table II-1. High Voltage and SAFE-CONN Connectors.
HV Connector SAFE-CONN Connector Description
J501 J401 HV & SafeConn Connect, Supply 1
J502 J402 Optional Connect, Supply 1
J503 J403 HV & SafeConn Connect, Supply 2
J504 J404 Optional Connect, Supply 2
Installing the Remote TSP/NEG Control Option
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DANGER: Voltages up to 7000V are present in the DIGITEL MPC. Turn off power and
disconnect AC input power cable before installing the Remote TSP/NEG Control option.
Figure II-2 shows an overview of the Remote TSP/NEG Control connections in the system.
DIGITEL
MPC Rear
Panel
Remote
TSP/NEG
Control
J2
CONTROL 1
2
3
4
COM
filaments
filament feedthrough
high current
cable
control
cable
J2505
TSP/NEG
CTRL
AC input
Figure II-2. Remote TSP/NEG Control Connections.
To install the Remote TSP/NEG Control, use the following procedure. Figure II-3 provides an
installation diagram.
Required Items
You need the following components to install the Remote TSP/NEG Control:
1. control cable
2. Remote TSP/NEG Control unit
3. high current cable
4. AC input power cable
Procedure
1. Mount the Remote TSP/NEG Control unit using the holes provided on the mounting
bracket (see Figure II-3).
2. Turn off power to the DIGITEL MPC and disconnect its AC input power cable.
3. Connect the control cable to J505 TSP/NEG CTRL on the rear panel of the
DIGITEL MPC. Connect the other end to J2 Control on the Remote TSP/NEG
Control unit.
control cable
connect
control cable
connect
ac
input
DIGITEL Rear Panel
Remote TSP/NEG
Control - Side View
high current
cable
Remote TSP/NEG
Control
Figure II-3. Diagram of Remote TSP/NEG Control.
CAUTION: Step 4 is a high current connection. Make sure that you have a secure
connection, or heating will occur.
4. Connect the high current cable to the filament feedthrough. Filament wires are
labeled as shown in Figure II-4.
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Figure II-4. High Current Cable.
5. Connect the AC input power cable to the Remote TSP/NEG Control unit.
6. Reconnect the AC input power cable to the DIGITEL MPC.
NOTE: If you need to connect a high current cable to the TSP/NEG unit, see Section 4,
Connecting a High Current Cable to TSP/NEG.
SAFE-CONN™ Installation on an Ion Pump
Use the following procedure to install a SAFE-CONN on the high-voltage feedthrough (HVFT)
of your ion pump.
Required Items
1. Parts:
1.1. a PEEK (Poly-Ether-Ether-Ketone) cylinder
1.2. two SS rings
2. Tools:
2.1. two flat-head screwdrivers
2.2. an SS installation tool and a plastic cylinder
Procedure
1. Place SS ring #1 on the 10 kV HVFT (Figure II-5).
2. Install the PEEK cylinder over the 10 kV HVFT with its inner diameter groove facing
away from the pump (Figure II-5). The inner diameter groove will locate/lock onto
the 10 kV HVFT tabs.
Figure II-5. SAFECONN Installation Diagram #1.
3. Use the two flat-headed screwdrivers prying against the mini-CFF, pry SS ring #1
over the PEEK cylinder and into the open groove (Figure II-6).
4. Using the SS installation tool and plastic cylinder, install SS ring #2 on the PEEK
cylinder.
4.1. Place the SS ring on the nose/ramp of the SS installation tool.
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Figure II-6. SAFECONN Installation Diagram #2.
4.2. Using the plastic cylinder, keep a constant steady pressure on the SS ring, while
keeping the installation tool, SS ring, and plastic cylinder assembly together.
4.3. Raise the assembly to the HVFT, and with a light tap on the plastic cylinder,
slide SS ring #2 into the open groove of the PEEK cylinder.
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III. Operation
Operation of the DIGITEL™ Multiple Pump Control (MPC) can be controlled by the operator
through the system computer software. Refer to the system operator’s guide for specific
operating procedures.
Section 3 (page 15), Operation, contains the following information for manual control of the
DIGITEL MPC.
•Front Panel Description identifies and describes the front panel controls and
indicators.
•Rear Panel Description identifies and provides signal pinouts for the rear panel
connectors.
•Operating the Ion Pump explains how to evacuate and start an ion pump.
•Using the Keypad provides a detailed explanation of keypad operation and its
associated display information.
•Display Messages gives a description in a table format of the status messages that
can appear on the display.
•Analog Outputs describes the monitor outputs for voltage and current.
•Serial Interface provides detailed information concerning the computer
communication interface.
•Menu Structure provides detailed flow chart on the menu structure.
Front Panel Description
Figure III-1 identifies the front panel controls and indicators on the DIGITEL™ MPC, which are
described in Table III-1.
HV
indicators Display Select
keys
Display 1
Display 2
power
switch Set Point
indicators (8)
Keypad
3.0E -- 10 TOR
1.3 Amps
Display
Select
Display
Select
DIGITEL MPC - Multiple Pump Control
Supply 1
Set PointSet Point
Power 1234567 8
High
Voltage
High
Voltage 1 2 3
4 5 6
7 8 9
ESC 0
ENTER Menu
TSP
Bake
High
Voltage
Operate
Set
Points
Mode
Select
Supply 2
Figure III-1. Front Panel Controls and Indicators.
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Table III-1. Front Panel Controls and Indicators.
Control Description
Main Power switch Turns main power on and off (1 = ON; 0 = OFF).
High Voltage indicators
(2) When high voltage (HV) is enabled to supply 1 or supply 2, the associated indicator on the front panel lights.
To enable HV manually, use the 9key on the front panel keypad to select High
Voltage Operate. Press the Display Select key for the appropriate power supply and
press ENTER.
Note: If SAFE-CONN interlock is not intact, high voltage will not turn on.
Supply 1, Supply 2
displays During normal mode, displays 1 & 2 show voltage, current, or pressure status information, as well as error codes. When in program mode, they display
corresponding data.
Display Select (2) keys During normal mode, press this key to select voltage, current, or pressure for display.
During program or menu mode — when an arrow on the display points to a Display
Select key, it is active. When active, press it to cycle through setup options.
Set Point indicators (8) A set point indicator LED lights when its associated output is energized.
Set points 1 through 4 are relay. Set points 5 through 8 are TTL.
Control Description
Keypad: Used as the primary method for manual control of the MPC.
0key (disable) To disable the keypad, press 0four times in succession during normal mode. All keys
except the Display Select keys are disabled.
1key (enable) To re-enable keypad operation, press 1four times in succession.
3, 6, 9or ←key selects one of the following four program modes:
Set Points During normal mode, press 3to select the Set Points program mode. The Set Points
section following Table III-2, provides detailed information on this key.
Bake During normal mode, press 6to select the Bake program mode. The Bake section
following Table III-2, provides detailed information on this key.
High Voltage Operate During normal mode, press 9to select High Voltage Operate, to allow the high
voltage on/off function. The High Voltage Operate section following Table III-2,
provides detailed information on this key.
TSP During normal mode, press the ←(backspace) key to select the TSP program mode.
The TSP section following this Table III-2, provides detailed information on this key.
Menu (blank key) During normal mode, press the blank key to select the menu mode, which is a
hierarchical system for setting unit parameters and preferences.
When in the menu mode, use it to scroll through the menu options. Refer to Table
III-3.
0through 9 keys When you select one of the program modes or the menu mode, use the numerical
keys to enter the desired data. Press ENTER to save or ESC to exit without saving.
Refer to Table III-2 and Table III-3.
←key When in program or menu mode, use the ←(backspace) key to correct errors when
keying in data.
ESC key While in menu or program mode, use this key to escape without saving changes.
When in a submenu, use it to move back up a level in the menu structure.
ENTER key Press this key to save setup data. It is also used in menu mode to step down to the
submenu.

Rear Panel Description
Figure III-2 identifies the rear panel connectors on the DIGITEL™ MPC. Connector pinouts are
given in the tables below.
HV connect - supply 1
safety ground cable
SafeConn connect - supply 1
Optional
SafeConn connect - supply 1
Optional
HV connect - supply 1
ac
input
J112
SER
INTFC
J505
TSP/NEG
CTRL
J104
SET PT
ANALOG
OUT
HIGH VOLTAGE OUT SAFETY INTERLOCK
J501
J502
J503
J504 J404
J403
J402
J401
J507
INPUT POWER
120/220V 50/60 HZ
J112
SER
INTFC J505
TSP/NEG
CTRL
J104
SET PT
ANALOG
OUT J506
Figure III-2. Rear Panel Connectors.
J104 SET PT ANALOG OUT (a 37-pin, female Sub-D connector) provides 8 set point signals,
and 4 voltage/current analog output signals.
Pin Setpoint Signal Pin Analog Output Signal
1 Set Point 1 (Relay) Common 20 … 28 Unused
2 500 mA, 28V, max. NC 29 GND2
3 NO 30 Analog HV Supply 1 Output
4 Set Point 2 (Relay) Common 31 GND2
5 500 mA, 28V, max. NC 32 Analog Current Output 1*
6 NO 33 GND2
7 Set Point 3 (Relay) Common 34 Analog Current Output 2*
8 500 mA, 28V, max. NC 35 GND2
9 NO 36 Analog HV Supply 2 Output
10 Set Point 4 (Relay) Common * Can be configured for Supply 1 or Supply 2
11 500 mA, 28V, max. NC current (I) output – See Analog Outputs.
12 NO
13, 14, 16, 18 GND1
15 Set Point 5 (TTL), 15 mA max.
17 Set Point 6 (TTL), 15 mA max.
19 Set Point 7 (TTL), 15 mA max.
37 Set Point 8 (TTL), 15 mA max.
J505 TSP/NEG CTRL (a 15-pin, female Sub-D connector) provides the control signals for the
Remote TSP/NEG Control.
Pin Signal Pin Signal Pin Signal
1 Current Sense COM 6 SCR Trig Out 11 K2 Coil
2 SCR Trig Pull-up 7 K3 Coil 12 Not Used
3 K4 Coil 8 +15V Return 13 Current XFMR +
4 +15V to TSP 9 Current XFMR – 14 Sync Signal GND
5 Voltage Sense 10 Sync Signal from TSP 15 K1 Coil
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J112 SER INTFC (a 9-pin, female Sub-D connector) routes the serial interface signals for the
four serial interface protocols – RS-232, PHI (Physical Electronics), RS-485, and RS-422.
RS-232 Operation PHI Operation RS-485 Operation RS-422 Operation
DCD 1 +TX 2 +TX 2 +RX 3
RXD 2 –TX 8 –TX 8 –RX 7
TXD 3 GND 5 GND 5 GND 5
GND 5 +RX 3
DSR 6 –RX 7
RTS 7
CTS 8
Operating the Ion Pump
Ensure that the pump has been installed according to instructions supplied with it. Install the
DIGITEL MPC according to its instructions.
•The DIGITEL MPC and pump must be grounded and have a safety ground strap
connecting them to each other.
•The high voltage cable must be attached to the MPC and the pump.
•The proper pump size must be selected from the menu mode.
•The MPC must have the correct output polarity/voltage for the pump.
Note: More power and current are required to start larger ion pumps or pumps started at
higher pressures. Use the full extent of your rough pumping before starting a pump to reduce
pump wear and time to UHV, to improve system ultimate pressure, and to give the most accurate
readings.
To Evacuate the Pump
Before you run an ion pump, it must be evacuated to a minimum vacuum of 1 x 10–3 Torr.
Details are best obtained from the pump manual, but in general, use the following procedure.
1. Rough pump down to 1x10–3 Torr or less (the lower the better).
2. Ensure that contaminants do not backstream into the ion pump. If you use a
mechanical pump, it must be well trapped to prevent oil back-streaming from the
mechanical pump to the ion pump.
3. If an ion pump is used or has been at atmospheric pressure, it may be necessary to
bakeout the pump into the roughing pump to achieve the best pressure. This is done
by heating the ion pump (<300°C with magnets) for a period of several hours until
heat soaked.
To Start the Pump
Use the following procedure to start the pump. If your DIGITEL MPC is configured for
POWER-LOSS restart, high voltage starts automatically when your turn on the DIGITEL.
1. Turn on main power to the DIGITEL MPC. If in POWER-LOSS restart, go to Step
4. If in manual restart, go to Step 2.
2. Press 9to select High Voltage Operate.
2.1. To turn supply 1 on (or off), press the top Display Select key to toggle to the
desired value.

2.2. To turn supply 2 on (or off), press the bottom Display Select key to toggle to the
desired value.
3. Press the ENTER key.
NOTE: If you turn a supply ON and have not set the pump size for that supply, the display
automatically goes to PUMP SIZE menu to allow you to set the value.
4. When voltage starts to rise above 700V, the pump starts. The roughing pump should
be valved off at this point. If the pump starts to stall when the roughing pump is
valved off (as indicated by a decrease in voltage), the roughing pump should be
valved back into the system. After voltage has increased above 3000V, the display
may be switched to current or pressure display (when starting the pump, the voltage
display mode is more sensitive to pressure changes).
Using the Controls
Display Selection
During normal mode, Supply 1 and Supply 2 displays show either voltage, current, or pressure.
Press the Display Select key (Figure III-3) next to each supply to cycle through these choices.
Voltage is the default upon power-up, but you can change it in the Preferences menu. Refer to
the pump display information in section 3, Setting Preferences (page 31).
Display
Select
F
F
Figure III-3. DISPLAY SELECT key
Disable and Enable
If you want to disable the keypad, press the 0key four times in succession during normal mode.
All keys except the Display Select keys are disabled. Press the 1 key four times in succession to
re-enable operation.
Keypad
The keypad (Figure III-4) consists of the following keys and are labeled:
0-9
←(backspace)
ESC
ENTER
The 3(Set Points), 6(Bake), 9(High Voltage Operate), and ←(TSP) keys have program
modes (Table III-2).
The 0key four times within two seconds disables keypad operation.
The 1key four times within two seconds enables keypad operation.
The blank key is the Menu mode key (Figure III-5 and Table III-3).
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1 2 3
4 5 6
7 8 9
ESP 0
ENTER
High
Voltage
Operate
Bake
Set
Points
TSP
Menu
Mode
Select
Figure III-4. Keypad.
The Menu key (Figure III-5 and Table III-3), which is the blank key, is a hierarchical system for
setting unit parameters and preferences. Refer to section 3, Menu Key (page 29) for information
on how to use these keys.
TSP
Menu
Figure III-5. Menu key.
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