| 1 | .. $Id: index.rst 592 2011-08-04 04:23:37Z jemian $ |
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| 2 | |
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| 3 | EPICS IOC support documentation |
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| 4 | -------------------------------------------------------------- |
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| 5 | |
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| 6 | The EPICS IOC support package consists of an EPICS database, |
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| 7 | an autosave request file to support the database, |
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| 8 | an example EPICS softIOC to run the database, |
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| 9 | a MEDM screen, and some test code to demonstrate |
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| 10 | the routine operations. |
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| 11 | |
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| 12 | goals |
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| 13 | ^^^^^^^^^^^^^^^ |
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| 14 | |
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| 15 | * uses EPICS alarms |
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| 16 | * sends email whenever alarm PV changes |
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| 17 | * alarm PV changes based on its calculation |
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| 18 | * default calculation watches .SEVR of free and avail |
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| 19 | * trip points set by user |
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| 20 | * default trip points are 500 (minor) and 50 (major) MB remaining on either free or avail |
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| 21 | * disk PV will be reset to previous value if new value is empty or path does not exist |
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| 22 | * period PV will be reset if it is not a number or if it is below 1.0 |
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| 23 | * update is forced early when certain PVs change (successfully): disk and period |
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| 24 | |
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| 25 | |
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| 26 | database |
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| 27 | ^^^^^^^^^^^^^^^ |
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| 28 | |
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| 29 | Supports client-side software that watches disk space |
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| 30 | on a single partition and generates alarms as the free |
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| 31 | space grows small. EPICS Alarms are used to signal |
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| 32 | for attention. Client-side software will be used to send |
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| 33 | email when $(P)$(D)df:alarm changes its value. |
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| 34 | Trip points for the alarms are in .HIGH and .HIHI fields |
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| 35 | of the "ao" records. |
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| 36 | |
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| 37 | macro parameters |
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| 38 | +++++++++++++++++++++++ |
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| 39 | |
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| 40 | ===== ============= =================================== |
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| 41 | macro typical value meaning |
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| 42 | ===== ============= =================================== |
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| 43 | P prj: IOC prefix |
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| 44 | D p300: specific device supported |
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| 45 | ===== ============= =================================== |
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| 46 | |
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| 47 | This database can be run in an EPICS softIoc (usually for development). |
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| 48 | See the source project for file ``epics/start_ioc.sh``.:: |
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| 49 | |
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| 50 | softIoc -m P=prj:,D=p300: -d epicsdf.db |
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| 51 | |
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| 52 | :note: softIoc is one of the tools built in EPICS base and |
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| 53 | can be found on the path |
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| 54 | ``${EPICS_BASE}/bin/${EPICS_HOST_ARCH}/softIoc`` |
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| 55 | |
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| 56 | process variables |
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| 57 | +++++++++++++++++++++++ |
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| 58 | |
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| 59 | The support database creates process variables to hold various values. |
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| 60 | The waveform PVs hold string values up to 1024 characters in length. |
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| 61 | |
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| 62 | ====================== ============= =================================== |
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| 63 | name type meaning |
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| 64 | ====================== ============= =================================== |
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| 65 | $(P)$(D)df:disk waveform disk partition being watched |
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| 66 | $(P)$(D)df:message waveform message to be sent by email |
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| 67 | $(P)$(D)df:email_list waveform list of email addresses |
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| 68 | $(P)$(D)df:total ao total space on the partition (MB) |
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| 69 | $(P)$(D)df:free ao free space (MB) |
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| 70 | $(P)$(D)df:avail ao available space |
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| 71 | $(P)$(D)df:used ao disk space in use (computed) |
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| 72 | $(P)$(D)df:free:pct ao percentage free space |
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| 73 | $(P)$(D)df:used:pct ao percentage used space |
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| 74 | $(P)$(D)df:avail:pct ao percentage available space |
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| 75 | $(P)$(D)df:period ao time between updates (s) |
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| 76 | $(P)$(D)df:alarm calcout calculated alarm condition |
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| 77 | ====================== ============= =================================== |
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| 78 | |
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| 79 | **Note:** To use either command line ``caget`` or ``caput`` with the |
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| 80 | waveform strings, it is necessary to use the ``-S`` option to |
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| 81 | indicate the use of a waveform string. Here are examples:: |
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| 82 | |
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| 83 | $ caget -S 15iddLAX:p100:df:disk |
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| 84 | /mnt/data |
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| 85 | $ caput -S 15iddLAX:p100:df:disk / |
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| 86 | Old : 15iddLAX:p100:df:disk /mnt/data |
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| 87 | New : 15iddLAX:p100:df:disk / |
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| 88 | |
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| 89 | |
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| 90 | alarm calculation |
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| 91 | ^^^^^^^^^^^^^^^^^^^ |
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| 92 | |
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| 93 | The alarm calculation uses a calcout record. |
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| 94 | The calcout records allows the user to reprogram the behavior as desired. |
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| 95 | In the default configuration, |
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| 96 | if the value of the $(P)$(D)df:alarm PV is non-zero, then |
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| 97 | disk space is running low. |
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| 98 | |
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| 99 | The alarm calculation watches |
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| 100 | the .SEVR field on the "free: and "avail" PVs. These PVs have alarm |
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| 101 | trip points for .LOW (minor) and .LOLO (major) alarms. |
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| 102 | By default, the trip points are set at 500 MB (minor) and 50 MB (major) |
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| 103 | space remaining with a hysteresis (.HYST) field of 5 MB. All these fields |
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| 104 | can be changed by users at run-time. Any change in either the |
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| 105 | "free: or "avail" PV will trigger a recalculation of the "alarm" PV |
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| 106 | through the forward link (.FLNK) fields of the "ao" record. |
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| 107 | |
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| 108 | :note: The present MEDM interface does not have entry boxes for changing the |
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| 109 | trip points now, nor for editing the calcout record. Changes to all these |
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| 110 | may be made from the command line through the caput command. |
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| 111 | |
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| 112 | database fragment:: |
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| 113 | |
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| 114 | record(ao, "$(P)$(D)df:free") |
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| 115 | { |
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| 116 | field(DESC, "free space") |
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| 117 | field(EGU, "MB") |
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| 118 | field(PREC, "3") |
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| 119 | field(HYST, "5") |
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| 120 | field(LOW, "500") |
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| 121 | field(LOLO, "50") |
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| 122 | field(LSV, "MINOR") |
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| 123 | field(LLSV, "MAJOR") |
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| 124 | field(FLNK, "$(P)$(D)df:alarm") |
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| 125 | } |
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| 126 | record(ao, "$(P)$(D)df:avail") |
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| 127 | { |
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| 128 | field(DESC, "available space") |
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| 129 | field(EGU, "MB") |
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| 130 | field(PREC, "3") |
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| 131 | field(HYST, "5") |
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| 132 | field(LOW, "500") |
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| 133 | field(LOLO, "50") |
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| 134 | field(LSV, "MINOR") |
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| 135 | field(LLSV, "MAJOR") |
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| 136 | field(FLNK, "$(P)$(D)df:alarm") |
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| 137 | } |
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| 138 | record(calcout, "$(P)$(D)df:alarm") |
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| 139 | { |
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| 140 | field(DESC, "any alarms will trigger this") |
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| 141 | field(CALC, "A>B?A:B") |
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| 142 | field(INPA, "$(P)$(D)df:free.SEVR NPP NMS") |
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| 143 | field(INPB, "$(P)$(D)df:avail.SEVR NPP NMS") |
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| 144 | field(EGU, "boolean") |
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| 145 | field(HOPR, "2") |
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| 146 | field(HIHI, "2") |
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| 147 | field(HIGH, "1") |
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| 148 | field(HHSV, "MAJOR") |
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| 149 | field(HSV, "MINOR") |
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| 150 | } |
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| 151 | |
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| 152 | |
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| 153 | |
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| 154 | MEDM client |
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| 155 | ^^^^^^^^^^^^^^^ |
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| 156 | |
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| 157 | The MEDM screen has been created to support the users and the code developer. |
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| 158 | It could be improved with user feedback. |
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| 159 | |
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| 160 | The macro parameters are defined the same as for the database. |
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| 161 | The support screen is typically started with a command such as:: |
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| 162 | |
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| 163 | medm -x -macro P=15iddLAX:,D=p100: epicsdf.adl & |
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| 164 | |
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| 165 | macro parameters |
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| 166 | +++++++++++++++++++++++ |
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| 167 | |
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| 168 | ===== ============= =================================== |
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| 169 | macro example value meaning |
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| 170 | ===== ============= =================================== |
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| 171 | P 15iddLAX: IOC prefix |
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| 172 | D p100: specific device supported |
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| 173 | ===== ============= =================================== |
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| 174 | |
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| 175 | .. image:: epicsdf_medm.jpg |
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| 176 | :alt: example MEDM screen for <tt>epicsdf</tt> |
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| 177 | |
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