What causes Okuma OSP alarm 1259?

Program issues G02/G03/G30-G35 while the tailstock body is connected (e.g. after M189 connect command). Axis move or turret index commanded in AUTO/MDI with the tailstock connected on a simple tow-along machine. Tailstock connection command issued while Y-axis control mode is active. Faulty EC input signals: control thinks the tailstock is connected when it is not.

How do I fix Okuma OSP alarm 1259?

1. Read the code number shown with the alarm: code None = An illegal G code (G02/G03/G30-G35) was commanded while the tow-along tailstock body is connected; code 2 = Simple tow-along spec: axis movement or turret indexing attempted with the tailstock body connected; code 3 = Axis move commanded in AUTO or MDI mode with the tailstock body connected; code 4 = Tailstock connection command issued while Y-axis control mode was active; code 5 = Home position return (OGL) commanded while the tow-along tailstock was connected; code 6 = G02/G03/G30-G35 commanded while the self-travelling tailstock is unclamped; code 7 = An axis other than W was moved while the self-travelling tailstock is unclamped; code 8 = W-axis command given without the required conditions: tailstock at back end, X-axis at plus limit, tailstock clamped, spindle stopped 2. Read the code on screen. Code None/2/3: the program moved an axis, indexed the turret, or used an illegal G code while connected - edit the program so the tailstock is disconnected before those commands, or for code 3 feed the axis with the pulse handle while connected. 3. Code 4: cancel Y-axis control mode first, then issue the tow-along tailstock connection command. 4. Code 5: separate the tow-along tailstock connection before commanding home position return (OGL). 5. Code 6/7: with the self-travelling tailstock unclamped, only W-axis moves are allowed - remove G02/G03/G30-G35 and any non-W axis move from that section of the program. 6. Code 8: before issuing a W-axis command, confirm the tailstock is at the back end, X-axis is at the plus limit, the self-travelling tailstock is clamped, and the main spindle is stopped. 7. If the tailstock is actually disconnected but the alarm persists, check the EC inputs: I/O check No.27 bit6 (connection confirmation) and bit7 (disconnection confirmation; ON when disconnected on the simple spec) - a stuck or miswired confirmation switch gives a false connected state.

Okuma OSP codes

axismd.ai

Okuma OSP Controller

Program/G-code · Intermediate

Alarm 1259

Okuma OSP Alarm A 1259 - Tow-along tailstock connecting

The control blocked a command because it was issued while the tow-along tailstock body was connected to the carriage. Circular interpolation, thread cutting, and similar G codes (G02/G03/G30-G35), axis moves, or turret indexing are not allowed in the connected state, so the program must separate the tailstock first or use the permitted feed method.

Okuma OSPProgram/G-codeIntermediate

1259

Okuma OSP Alarm A 1259 - Tow-along tailstock connecting

Tow-along tailstock connecting

Common Causes

Program issues G02/G03/G30-G35 while the tailstock body is connected (e.g. after M189 connect command)
Axis move or turret index commanded in AUTO/MDI with the tailstock connected on a simple tow-along machine
Tailstock connection command issued while Y-axis control mode is active
Faulty EC input signals: control thinks the tailstock is connected when it is not

Troubleshooting Steps

1Read the code number shown with the alarm: code None = An illegal G code (G02/G03/G30-G35) was commanded while the tow-along tailstock body is connected; code 2 = Simple tow-along spec: axis movement or turret indexing attempted with the tailstock body connected; code 3 = Axis move commanded in AUTO or MDI mode with the tailstock body connected; code 4 = Tailstock connection command issued while Y-axis control mode was active; code 5 = Home position return (OGL) commanded while the tow-along tailstock was connected; code 6 = G02/G03/G30-G35 commanded while the self-travelling tailstock is unclamped; code 7 = An axis other than W was moved while the self-travelling tailstock is unclamped; code 8 = W-axis command given without the required conditions: tailstock at back end, X-axis at plus limit, tailstock clamped, spindle stopped
2Read the code on screen. Code None/2/3: the program moved an axis, indexed the turret, or used an illegal G code while connected - edit the program so the tailstock is disconnected before those commands, or for code 3 feed the axis with the pulse handle while connected.
3Code 4: cancel Y-axis control mode first, then issue the tow-along tailstock connection command.
4Code 5: separate the tow-along tailstock connection before commanding home position return (OGL).
5Code 6/7: with the self-travelling tailstock unclamped, only W-axis moves are allowed - remove G02/G03/G30-G35 and any non-W axis move from that section of the program.
6Code 8: before issuing a W-axis command, confirm the tailstock is at the back end, X-axis is at the plus limit, the self-travelling tailstock is clamped, and the main spindle is stopped.
7If the tailstock is actually disconnected but the alarm persists, check the EC inputs: I/O check No.27 bit6 (connection confirmation) and bit7 (disconnection confirmation; ON when disconnected on the simple spec) - a stuck or miswired confirmation switch gives a false connected state.

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.