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2.5-meter Telescope Controls & Interlock System
Receiver/Splitter Chassis Input Table
Revised 4/7/2000
The following table lists the inputs into the receiver/splitter chassis for the 2.5-meter telescope axes control and interlock system. Some of the inputs come directly from mechanical devices such as stop buttons, limit switches, etc. Other inputs are provided by the interlock system programmable logic controller (PLC) based on the state of various system conditions. The logic behind these inputs is graphically described in interlock system logic diagrams.
The receiver/splitter chassis provides the capability for bypassing each input channel. Bypassing a channel effectively bypasses an interlock. In several cases, bypassing a single channel effectively disables all interlocks protecting a particular telescope axis or system. These instances are noted in the table.
The interlock system is carefully designed to protect the telescope. Disabling all or part of this system may result in serious damage to the telescope. Bypassing interlocks must only be done after the relative logic diagram has been reviewed and the consequences of the bypass fully understood.
Questions regarding inputs into the receiver/splitter chassis, or to the interlock system in general, should be addressed to
John Anderson (630.840.4973), or Glenn Federwitz (630.840.4836).
| Slot | CH | Input Device | Description | Affects |
| 1 | 0 | tcc_ stop | Provision for input from TCC to disable telescope motion. Not implemented. | AZ,ALT,ROT Motion |
| 1 | cr_stop | Stop Button in the 2.5-m Control Room | AZ,ALT,ROT Motion | |
| 2 | spare_s1_c2 | spare channel | N.U. | |
| 3 | fiber_signal_loss | Indicates the fiber optic signal from the main building is not functioning | N.U. | |
| 4 | n_wind_stop | Stop Button on the north side of the windbaffle frame | AZ,ALT,ROT Motion | |
| 5 | n_fork_stop | Stop Button on the northeast telescope fork | AZ,ALT,ROT Motion | |
| 6 | s_rail_stop | Stop Button on the north railing - outside | AZ,ALT,ROT Motion | |
| 7 | n_rail_stop | Stop Button on the south railing - outside | AZ,ALT,ROT Motion | |
| 2 | 0 | w_rail_stop | Stop Button on the west railing - outside | AZ,ALT,ROT Motion |
| 1 | n_lower_stop | Stop Button on the north wall in the lower level | AZ,ALT,ROT Motion | |
| 2 | s_lower_stop | Stop Button on the south wall in the lower level | AZ,ALT,ROT Motion | |
| 3 | e_lower_stop | Stop Button on the east wall in the lower level | AZ,ALT,ROT Motion | |
| 4 | w_lower_stop | Stop Button on the west wall in the lower level | AZ,ALT,ROT Motion | |
| 5 | s_fork_stop | Stop Button on the north side of the windbaffle frame | AZ,ALT,ROT Motion | |
| 6 | spare_s2_c6 | spare channel | N.U. | |
| 7 | spare_s2_c7 | spare channel | N.U. | |
| 3 | 0 | alt_mtr_up_perm | Permit from PLC Inhibits telescope altitude upward motion See logic diagram EB-355925 for details (Output from PLC to Splitter Chassis) | Alt UP Motion |
| alt_mtr_up_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE TELESCOPE UP DIRECTIONAL SOFT LIMIT. | ||||
| 1 | alt_mtr_dn_perm | Permit from PLC Inhibits telescope altitude downward motion. See logic diagram EB-355925 for details. (Output from PLC to Splitter Chassis) | Alt DOWN Motion | |
| alt_mtr_dn_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE TELESCOPE UP DIRECTIONAL SOFT LIMIT. | ||||
| 2 | alt_mtr1_perm | Permit to telescope altitude motor #1 allowing bi-directional motion. (Hard Wired Signal) | Alt Motor 1 Motion | |
| alt_mtr1_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING***BYPASSING THIS INTERLOCK EFFECTIVELY DISABLES NUMEROUS INTERLOCKS PROTECTING TELESCOPE ALTITUDE MOTION. REFER TO LOGIC DIAGRAM EB-355925 FOR DETAILS. | ||||
| 3 | alt_mtr2_perm | Permit to telescope altitude motor #2 allowing bi-directional motion. (Hard Wired Signal) | Alt Motor 2 Motion | |
| alt_mtr2_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING***BYPASSING THIS INTERLOCK EFFECTIVELY DISABLES NUMEROUS INTERLOCKS PROTECTING TELESCOPE ALTITUDE MOTION. REFER TO LOGIC DIAGRAM EB-355925 FOR DETAILS. | ||||
| 4 | wind_alt_mtr_perm | Permits bi-directional motion of the windbaffle altitude motors. See logic diagram EB-355925 for details. (Hard Wired Signal) | Alt Wind Motion | |
| wind_alt_mtr_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK CHANNEL EFFECTIVELY DISABLES NUMEROUS INTERLOCKS PROTECTING WINDBAFFLE ALTITUDE MOTION. REFER TO LOGIC DIAGRAM EB-355925 FOR DETAILS. | ||||
| 5 | alt_plc_perm | Permit from the PLC that allows telescope altitude motion. See logic diagram EB-355925 for details. (Output from PLC to Splitter Chassis) | Alt Motion | |
| alt_plc_perm-in | (Input to PLC) Status of splitter chassis channel output | |||
| 6 | wind_alt_plc_perm | Permit from PLC that allows windbaffle altitude motion. See logic diagram EB-355925 for details. (Output from PLC to Splitter Chassis) | Alt Wind Motion | |
| wind_alt_plc_perm-in | (Input to PLC) Status of splitter chassis channel output | |||
| 7 | az_stow_3a | The 3rd contact from Stow A this with Stow B lets the Interlocks know that the Telescope is in the stow range | Building Motion | |
| 4 | 1 | az_mtr_cw_perm | Permit from PLC allowing telescope clockwise motion. Refer to logic diagram EB-355926 for details. (Output from PLC to Splitter Chassis) | AZ CW Motion |
| az_mtr_cw_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE TELESCOPE CW DIRECTIONAL SOFT LIMIT. | ||||
| 2 | az mtr_ccw_perm | Permit from PLC allowing telescope counterclockwise motion. (Output from PLC to Splitter Chassis) | AZ CCW Motion | |
| az mtr_ccw_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE TELESCOPE CCW DIRECTIONAL SOFT LIMIT | ||||
| 3 | az_mtr1 perm | Permit to telescope azimuth motor #1 allowing bi-directional motion. (Hard Wired Signal) | AZ Motor 1 Motion | |
| az_mtr1 perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING***BYPASSING THIS INTERLOCK EFFECTIVELY DISABLES NUMEROUS INTERLOCKS PROTECTING TELESCOPE AZIMUTH MOTION. REFER TO LOGIC DIAGRAM EB-355926 FOR DETAILS. | ||||
| 4 | az_mtr2_perm | Permit to telescope azimuth motor #2 allowing bi-directional motion. (Hard Wired Signal) | AZ Motor 2 Motion | |
| az_mtr2_perm-in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING***BYPASSING THIS INTERLOCK EFFECTIVELY DISABLES NUMEROUS INTERLOCKS PROTECTING TELESCOPE AZIMUTH MOTION. REFER TO LOGIC DIAGRAM EB-355926 FOR DETAILS. | ||||
| 5 | wind_az_mtr_perm | Permits bi-directional motion of the windbaffle azimuth motors. See logic diagram EB-355926 for details. (Hard Wired Signal) | AZ Wind Motion | |
| wind_az_mtr_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK CHANNEL EFFECTIVELY DISABLES NUMEROUS INTERLOCKS PROTECTING WINDBAFFLE AZIMUTH MOTION. REFER TO LOGIC DIAGRAM EB-355926 FOR DETAILS. | ||||
| 6 | wind_az_plc_perm | Inhibits windbaffle azimuth motion unless the 15-deg stop is engaged. (Output from PLC to Splitter Chassis) | AZ Wind Motion | |
| wind_az_plc_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| 7 | az_stow_3b | The 3rd contact from Stow B this with Stow A lets the Interlocks know that the Telescope is in the stow range | Building Motion | |
| 5 | 0 | rot_mtr_cw_perm | PLC permit that allows rotator motion in clockwise direction. (Output from PLC to Splitter Chassis) | Rot CW Motion |
| rot_mtr_cw_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE ROTATOR CW DIRECTIONAL SOFT LIMIT. | ||||
| 1 | rot_mtr_ccw_perm | PLC permit that allows rotator motion in counterclockwise direction. Disabled if soft limit reached. (Output from PLC to Splitter Chassis) | Rot CCW Motion | |
| rot_mtr_ccw_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE ROTATOR CCW DIRECTIONAL SOFT LIMIT. | ||||
| 2 | rot_mtr_perm | Permit enabling rotator bi-directional motion. (Hard Wired Signal) | Rot Motion | |
| rot_mtr_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK CHANNEL EFFECTIVELY DISABLES ALL HARD LIMITS PROTECTING ROTATOR MOTION. REFER TO LOGIC DIAGRAM EB-355925 FOR DETAILS. | ||||
| 3 | spare_s5_c3 | spare channel | N.U. | |
| 4 | bldg_perm | Permit enabling building motion. (Hard Wired Signal) | Building Motion | |
| bldg_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| ***WARNING*** BYPASSING THIS INTERLOCK DISABLES THE BUILDING MOTION INTERLOCKS. REFER TO LOGIC DIAGRAM EB-355939 FOR DETAILS | ||||
| 5 | rot_plc_perm | Telescope rotator motor overcurrent interlock. Disables rotator motion if motor overheating sensed. (Output from PLC to Splitter Chassis) | Rot Motion | |
| rot_plc_perm_in | (Input to PLC) Status of splitter chassis channel output | |||
| 6 | hatch_cls | Hatch door switches prevent building motion unless hatch doors are closed. | Building Motion | |
| 7 | alt_les_2d5_limit | Alt has to be below 2.5 degrees for building motion | Building Motion | |
| 6 | 0 | alt_grt_0d3_limit | Altitude lower "hard" stop. Disables telescope and windbaffle drive motors. | Alt Motion |
| 1 | alt_locking_pin_out | Locking pin "not out" Disables telescope and windbaffle Altitude drive motors | Alt Motion | |
| 2 | alt_les_90d5_limit | Altitude upper "hard" stop. Disables telescope and windbaffle Altitude drive motors. | Alt Motion | |
| 3 | bldg_on_alt | Signal that indicates that the building is on. Used on Altitude Axis | Alt Motion | |
| 4 | az_109_131_limit_1 | The 1st contact from the Azimuth building "on" motion "hard" limits | Alt Motion | |
| 5 | alt_grt_18d6_limit_1 | The 1st contact from the Altitude "hard" limit for the railing | Alt Motion | |
| 6 | az_stow_1a | The 1st contact from Stow A this with Stow B lets the Interlocks know that the Telescope is in the stow range | Alt Motion | |
| 7 | az_stow_1b | The 1st contact from Stow B this with Stow A lets the Interlocks know that the Telescope is in the stow range | Alt Motion | |
| 7 | 0 | alt_grt_83_limit_1 | The 1st contact from the Altitude "hard" limit for full azimuth motion with building "on" | Alt Motion |
| 1 | bldg_clear_alt | Signal that indicates that the building is off far enough for safe operation. Used on Atitude axis | Alt Motion | |
| 2 | az_stow_2a | The 2nd contact from Stow A this with Stow B lets the Interlocks know that the Telescope is in the stow range | Alt Motion | |
| 3 | az_stow_2b | The 2nd contact from Stow B this with Stow A lets the Interlocks know that the Telescope is in the stow range | Alt Motion | |
| 4 | deg_15_stop_ext | 15 degree stop fully extended status | Alt Motion | |
| 5 | alt_grt_18d6_limit_2 | The 2nd contact from the Altitude "hard" limit for the railing | Alt Motion | |
| 6 | alt_slip | Slip detection trip output signal | Alt Motion | |
| 7 | alt_velocity_limit | Velocity limit output signal | Alt Motion | |
| 8 | 0 | az_dir_cw | Azimuth Clockwise direction switch | Az Motion |
| 1 | az_dir_ccw | Azimuth Counter Clockwise direction switch | Az Motion | |
| 2 | az_neg_170a_cw | The 1st contact from the Azimuth 170 degree Clockwise "hard" limit switch | Az Motion | |
| 3 | az_pos_410a_ccw | The 1st contact from the Azimuth 410 degree Counter Clockwise "hard" limit switch | Az Motion | |
| 4 | az_neg_170b_cw | The 2nd contact from the Azimuth 170 degree Clockwise "hard" limit switch | Az Motion | |
| 5 | az_pos_410b_ccw | The 2nd contact from the Azimuth 410 degree Counter Clockwise "hard" limit switch | Az Motion | |
| 6 | spare_s8_c6 | spare channel | N.U. | |
| 7 | spare_s8_c7 | spare channel | N.U. | |
| 9 | 0 | alt_grt_18d6_limit_3 | The 3rd contact from the Altitude "hard" limit for the railing | AZ Wind Motion |
| 1 | bldg_on_az | Signal that indicates that the building is on. Used on Azimuth axis | Az Motion | |
| 2 | az_109_131_limit_2 | The 2nd contact from the Azimuth building "on" motion "hard" limits | Az Motion | |
| 3 | alt_grt_83_limit_2 | The 2nd contact from the Altitude "hard" limit for full azimuth motion with building "on" | Az Motion | |
| 4 | bldg_clear_az | Signal that indicates that the building is off far enough for safe operation. Used on Azimuth axis | Az Motion | |
| 5 | spare_s9_5 | spare channel | N.U. | |
| 6 | az_slip | Slip detection trip output signal | Az Motion | |
| 7 | az_velocity_limit | Velocity limit output signal | Az Motion | |
| 10 | 0 | rot_dir_cw | Rortator Clockwise direction switch | Rot Motion |
| 1 | rot_dir_ccw | Rotator Counter Clockwise direction switch | Rot Motion | |
| 2 | rot_neg_200a_cw | The 1st contact from the Rotator 200 degree Clockwise "hard" limit switch | Rot Motion | |
| 3 | rot_pos_380a_ccw | The 1st contact from the Rotator 380 degree Counter Clockwise "hard" limit switch | Rot Motion | |
| 4 | rot_neg_200b_cw | The 2nd contact from the Rotator 200 degree Clockwise "hard" limit switch | Rot Motion | |
| 5 | rot_pos_380b_ccw | The 2nd contact from the Rotator 380 degree Counter Clockwise "hard" limit switch | Rot Motion | |
| 6 | rot_slip | Slip detection trip output signal | Rot Motion | |
| 7 | rot_velocity_limit | Velocity limit output signal | Rot Motion | |
Last updated on 4/7/2000
Send comments: jea@fnal.gov